5.6: Long-Acting Reversible Contraception
By the end of this section, you will be able to:
- Compare and contrast the different types of intrauterine contraception devices
- Compare and contrast the different types of contraceptive implant devices
- Discuss the benefits and complications of LARC devices
A long-acting reversible contraception (LARC) option is the most effective form of contraception available (ACOG, 2024); LARCs include intrauterine contraception devices and contraceptive implants. The efficacy of these devices is the same as or better than that of female sterilization. However, LARCs are easily placed in the office, and no activity restrictions or downtime is necessary after insertion. Additionally, when the person desires to discontinue this method, the return to fertility is immediate. LARCs are cost-effective and can be used for extended periods of time, some for up to 10 years. They do not provide protection against STIs.
Long-Acting Reversible Contraception: Benefits and Complications
The major benefit to LARCs is their high degree of protection against unintended pregnancy , a pregnancy that is unwanted or mistimed (Kopp Kallner, 2018). Research has consistently shown that LARCs are the most effective choices for people in their childbearing years. Interestingly, LARC use is still very low among adolescents, a group at high risk of unintended pregnancy and low adherence to contraception. Nurses in contraceptive clinics can advocate for this high-risk group to choose LARC methods, highly effective contraception that is not dependent on teens remembering to use it.
Benefits
The risks associated with LARC methods are very low and without the risks of blood clots, stroke s, and myocardial infarction that are present with estrogen-containing methods. This benefit allows higher-risk persons the option of safe, reliable contraception. In addition, when using a LARC method, the occurrence of amenorrhea is high. The absence of menstruation in a person with ovaries and a uterus, who is of reproductive age is considered amenorrhea . Persons with anemia due to menorrhagia, very heavy or prolonged menstrual bleeding, will have minimal monthly bleeding, offering protection from anemia. Use of LARCs also greatly reduces the incidence of dysmenorrhea , especially related to endometriosis . The levonorgestrel -releasing intrauterine contraception ( LNG-IUC ) reduces the risk for endometrial cancer by preventing thickening of the endometrium. Choosing to use LARCs offers persons privacy with their birth control choices. When using an intrauterine device or a contraceptive implant, the person has no packages of contraceptive pills and no tasks to do before acts of intercourse, and the device cannot be seen by others. The patient is in full control of their contraceptive choice, and that can feel very empowering. Another benefit to choosing a LARC is the immediate return to fertility once the implant or intrauterine device is removed. The nurse emphasizes this immediate return of fertility, as it can be a benefit for people wanting to conceive; it can be a drawback for others who are not seeking pregnancy.
Complications
Although they are not common, complications for a person choosing LARCs can arise. These complications will be discussed to ensure the person is a good candidate for this method. It is also important when considering use of a LARC that all persons be provided the information they need to give informed consent for it (ACOG, 2024).
Pregnancy
One complication that could occur with a LARC in place is pregnancy, and it must be managed as soon as it is confirmed. LARCs containing progesterone , which causes the cilia in the fallopian tubes to slow, increase the risk for ectopic pregnancy (Hatcher, 2018). The nurse educates the patient to monitor for symptoms of pregnancy, to check for IUC strings monthly, and to notify their provider immediately if they become pregnant (ACOG, 2024). Pregnancy means that the current LARC must be removed and a decision about the future of the pregnancy must be made.
Expulsion or Misplacement of the IUC
A complication that can occur with an IUC is expulsion or misplacement of the device. If the person finds the IUC in their cervix, internal os, or outside their body, they must contact their provider to have the device removed completely and replaced if they desire (ACOG, 2024). Expelled or misplaced IUCs have a very high rate of unintended pregnancies and must be managed immediately. Placement after delivery of the placenta has the highest expulsion rate.
Contraceptive implants must be palpated monthly by the patient to ensure correct placement. If the person cannot feel the implant in the correct place, they must contact their provider to ensure correct placement and rule out unintended pregnancy. These patients should also be advised to use a backup method of contraception until placement can be confirmed and pregnancy can be ruled out (ACOG, 2024).
Perforation
Uterine perforation and extrusion of the IUC into the peritoneal cavity are very rare complications; however, they can occur with placement of the device (ACOG, 2024). The symptoms of perforation likely occur at time of placement, but the nurse educates the person to be aware of heavy vaginal bleeding, severe cramping, abdominal pain, and fever after IUC placement.
Pelvic Inflammatory Disease
The risk for pelvic inflammatory disease (PID) , an infection of the female reproductive organs, when a person has intrauterine contraception is not necessarily increased overall, but it does increase in the first 3 weeks after placement (CDC, 2021). It most often occurs when sexually transmitted bacteria spread from the vagina to the uterus, fallopian tubes, or ovaries. Should the patient be diagnosed with PID while the IUC is in place, they should receive treatment according to the most recent CDC guidelines and have close clinic follow-up (CDC, 2021). The IUC can remain in place; however, if no clinical improvement is seen in 48 to 72 hours of initiating treatment, the clinician should remove the IUC. An unfortunate side effect of PID is the risk for infertility due to scarring of the fallopian tubes. The nurse can provide emotional support, education about other contraceptive choices, and information regarding the treatment and prevention of pelvic inflammatory disease.
Table 5.13 summarizes the pros, cons, and efficacy of the different LARCs.
| Method | Pros | Cons | Perfect Use Efficacy (per 100 couples per year) |
|---|---|---|---|
| LNG-IUC | Effective for 3 to 8 years, reversible, decrease menstrual cramps and heavy bleeding, can cause person to become amenorrheic, excellent for persons who cannot remember to take a pill, immediate return to fertility | Irregular bleeding, headache, ovarian cysts, vulvovaginitis | 99.8% |
| Copper T380A | Effective for 10 years, very few contraindications, excellent for persons who cannot remember to take a pill, immediate return to fertility | Heavier and more painful menses | 99.8% |
| Contraceptive implant | Effective for 3 years, excellent for persons who cannot remember to take a pill, immediate return to fertility | Irregular bleeding, possible pain at insertion site, headache, gastrointestinal (GI) difficulties, insertion site infection | 99% |
Intrauterine Contraception Devices
An intrauterine contraception (IUC) device (IUD) is a small, plastic T-shaped contraceptive device that is placed inside the uterus to prevent pregnancy. Use of the copper-containing IUC (Paragard) and the IUCs containing levonorgestrel (LNG-IUC) has increased tremendously in the past 20 years, from 2.4 percent in 2002 to 14 percent in 2017 (Daniels & Abma, 2020; KFF, 2020). The population with the highest use of IUCs are those aged 25 to 34 years, 60 percent higher than younger persons aged 20 to 24 years (KFF, 2020). Since LARC products came onto the market, the number of unintended pregnancies and induced abortion s has decreased (Espey & Hofler, 2017). One research study in Colorado noted that as LARC use increased by 5 percent to 19 percent in low-income teenagers and young persons, birth rates decreased by 29 percent, and abortion rates decreased by 34 percent (Espey & Hofler, 2017). Nurses can educate persons at high risk for unintended pregnancies (adolescents and low-income persons) and persons with little access to contraceptives (those who are homeless, of low socioeconomic status, or rural) about the long-term value of LARCs. The cost-benefit ratio leans toward LARCs as opposed to unintended pregnancies and abortions.
LNG-Intrauterine Contraception
LNG-IUCs are T-shaped intrauterine devices made of polydimethylsiloxane and containing levonorgestrel on the stem of the device (Dickey & Seymour, 2021) (Figure 5.14). The mechanism of action for LNG-IUCs is slightly different than for other progesterone-only methods, as the devices suppress ovulation in only 25 percent to 55 percent of cycles (Dickey & Seymour, 2021). The LNG-IUC alters the environment of the endometrium and prevents fertilization of the ovum by changing the viscosity of cervical mucus , making an uninhabitable environment for sperm and decreasing the motility and mobility of sperm (Dickey & Seymour, 2021). LNG-IUCs do not disrupt already fertilized ova (Bayer Pharmaceuticals, 2023; Espey & Hofler, 2017). Side effects include irregular bleeding, ovarian cysts, headache, and vulvovaginitis. Contraindications include pregnancy, uterine anomalies, pelvic infection, or reproductive tract or breast cancers (Dickey & Seymour, 2021).
The LNG-IUC has many advantages. Perfect and typical effectiveness are the same, 99.8 percent (Hatcher, 2018). It prevents proliferation of the endometrium, reduces menstrual pain, provides immediate return to fertility , and causes amenorrhea in 6 percent to 20 percent of users, depending on the amount of progesterone in the device (Dickey & Seymour, 2021). In persons who suffer from very heavy periods, many times a clinician will offer to place an LNG-IUC to thin the uterine lining and decrease menstrual bleeding (Hatcher, 2018). Levonorgestrel ( Mirena and Liletta ) can protect against pregnancy for up to 7 and 6 years, respectively, and can be used to treat menorrhagia for up to 5 years (Bayer Pharmaceuticals, 2023). Kyleena can stay in place and remain effective for pregnancy prevention for 5 years (Bayer Pharmaceuticals, 2023). Skyla, which is approved for up to 3 years of use, and Kyleena are excellent options for adolescents because the IUC frame is smaller than those of Mirena and Liletta (Bayer Pharmaceuticals, 2023).
Using LNG-IUC during Perimenopause
During perimenopause, many persons experience abnormal bleeding that can be light or very heavy and can be unexpected. Some perimenopausal persons carry extra clothes or pants with them because of unexpected very heavy bleeding. These persons can benefit from the LNG-IUC. The LNG-IUC causes a thin uterine lining, preventing heavy bleeding. The device is not contraindicated for use during perimenopause.
Paragard Intrauterine Device
Paragard , the copper T380A IUC , is a T-shaped device made of polyethylene with copper wire wrapped around the stem and arms of the device (Figure 5.15). Paragard has Food and Drug Administration (FDA) approval for 10 continuous years of use with an effectiveness rate of 99.4 percent to 99.9 percent (Hatcher, 2018). The mechanism of action is two-fold: the plastic and metal frame acts as a foreign body and causes inflammation in the uterus, and the inflammation causes a toxic environment that decreases sperm mobility and survival (Hatcher, 2018). Because of this inflammation, however, menstrual bleeding is heavier than prior to insertion of the IUC. This bleeding and cramping are the most common complaints from patients who use this method. Abnormal bleeding after placement can last 2 to 6 weeks while the uterus adjusts to the device. The patient should never fill more than one pad an hour, and if bleeding continues past 6 weeks, the person should call the clinic.
Because this IUC is hormone-free, very few contraindications exist, but those that do include pregnancy, current genital tract infection, uterine abnormalities, and copper allergy or Wilson’s disease (Hatcher, 2018). The nurse recommends Paragard to persons desiring a very effective, long-term contraceptive that is nonhormonal, such as those who are breast-feeding, who have religious reasons for not desiring hormones, smokers, and those with risk for thromboembolic disorders.
Patient Education for IUCs
After placement of the IUC, the nurse educates the person to check the IUC strings at the cervix monthly. If the strings are not felt, the patient should call the clinic and be seen to verify placement. Rare complications associated with IUC use include expulsion, method failure, and uterine perforation (Hatcher, 2018). Because of these complications, the nurse educates the patient using the PAINS acronym and explains that if any of those symptoms occur, the patient will need to get to an emergency department immediately for IUC placement check.
PAINS
The nurse educates the person to call the office with the following concerns:
P: Period late or missing; spotting after having stopped bleeding
A: Abdominal pain that is sharp and severe
I: Infection (vaginal discharge or smell)
N: Not feeling well (fever, tired, achy, chills)
S: Strings not being felt
If the patient experiences any of these symptoms, the nurse advises them to call the office immediately or go to the closest emergency department for evaluation.
Intrauterine Contraception: Mirena IUC
Nurses are often the gatekeepers in clinics, managing messages between clinicians and patients, especially after visits. Having a good understanding of how the intrauterine device works, what side effects are expected versus unexpected, and how long each device might last can help alleviate a lot of stress for both the nurse and the patient. Intrauterine contraceptive devices are gaining in popularity because this method of contraception can last as long as 10 years with an effective rate as high as 99.9 percent (CDC, 2023d).
- Generic Name: levonorgestrel
- Trade Name: Mirena (Skyla, Liletta, or Kyleena)
- Class/Action: hormonal contraceptive, progestin
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Route/Dosage:
intrauterine
- Kyleena: single dose 19.5 mg progesterone system intrauterine contraceptive
- Liletta: single dose 52 mg progesterone system intrauterine contraceptive
- Mirena: single dose 52 mg progesterone system intrauterine contraceptive
- Skyla: single dose 13.5 mg progesterone system intrauterine contraceptive
- High Alert/ Black Box Warning: None
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Indications
: FDA approved for contraception, menorrhagia, emergency contraception.
- Non-FDA uses: endometrial hyperplasia (a condition in which the endometrium of the uterus becomes very thick, causing unusual bleeding), endometriosis and perimenopausal symptoms.
- Mechanism of Action: Levonorgestrel is a synthetic progesterone that sometimes inhibits ovulation and inhibits sperm from reaching the egg because of thickening of cervical mucus.
- Contraindications: acute liver disease, acute history of pelvic inflammatory disease, known or suspected breast carcinoma, conditions associated with increased susceptibility to infections (e.g., leukemia, AIDS, IV drug abuse) including pelvic infections, congenital or acquired pelvic anomaly that distorts the uterine cavity, genital bleeding with unknown cause, infected abortion in the past 3 months, thrombophlebitis or thromboembolic disorders, untreated vaginitis or cervicitis, known or suspected progestin-sensitive cancer, known or suspected hormone-sensitive cancer and known or suspected uterine or cervical neoplasia, or unresolved, abnormal Pap smear.
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Adverse Reactions/Side Effects:
The following adverse drug reactions and incidences are derived from product labeling unless otherwise specified:
- Cardiovascular: Myocardial infarction
- Neurologic: Dizziness, headache, migraine
- Dermatologic: Acne
- Gastrointestinal: Abdominal pain, nausea
- Reproductive: Abnormal vaginal bleeding, amenorrhea, breast tenderness, dysmenorrhea, vaginitis, vulvovaginitis
- Nursing Implications: Witness consent. Review patient education with the family. Remain in the room to assist while procedure is being completed. Document in the patient’s chart.
- Parent/Family Education: The nurse educates the patient that they should periodically place a clean finger into the vagina and check for IUC strings near the cervix. Some cramping and bleeding intermittently for 2 to 6 weeks is normal after placement of an intrauterine contraception device (IUC), and irregular bleeding can be expected for 3 months. The patient may experience their normal menses or may not. The nurse provides education to the patient before they leave the office about calling to report heavy bleeding; pain with intercourse; abdominal pain; signs of infection including fever, chills, and malaise; and missing strings. If the person becomes pregnant while the IUC is in place, the nurse educates them to come back to the clinic immediately for an appointment.
Contraceptive Implant: Nexplanon
The contraceptive implant Nexplanon is a contraceptive device 4 cm in length and 2 mm in diameter, made of an ethylene vinyl acetate copolymer core containing etonogestrel surrounded by an ethylene vinyl copolymer skin (Dickey & Seymour, 2021) (Figure 5.16). The copolymer skin allows release of the etonogestrel over a 3-year period (Dickey & Seymour, 2021). The implant is very effective, with a perfect and typical effectiveness rate of 99 percent (Hatcher, 2021). It is inserted either in the hospital during the postpartum period or in the office; it is removed in the office by a trained clinician. The device lies subdermally on the underside of the arm above the medial epicondyle. The skin is injected with lidocaine for anesthesia, a small incision is made, and the device is placed by a disposable introducer. The arm is then wrapped to prevent bleeding. No sutures are necessary. The implant’s mechanism of action is to suppress ovulation, thicken cervical mucus, and alter the endometrial lining (Dickey & Seymour, 2021).
Side Effects of Nexplanon
Side effects include abnormal bleeding, changes in menstrual cycle, including amenorrhea, gastrointestinal difficulties, headaches, vaginitis, and ovarian cysts (Dickey & Seymour, 2021). Some people experience increased acne and weight gain. Complications related to the insertion of the device include pain at the insertion site, hematoma formation, and incorrect insertion (Dickey & Seymour).
Patient Education
The nurse demonstrates how to palpate for the device and instructs the person to palpate it occasionally to ensure correct placement. The person should be instructed to call the office if vaginal bleeding exceeds one pad an hour, or, if they experience any of the PAINS symptoms listed earlier. The nurse also stresses the importance of having the device removed after 3 years.


11.3: Questions to Guide Your Reading
1. How did the geography of Central Asia have an impact on its history?
2. In what way did the Turkic migrations change the culture of Central Asia?
3. How did the nomadic way of life facilitate the Turkic conquest of the region?
4. The process of Islamization took place over centuries. What helped to expedite the conversion process?
5. How did Genghis Khan differ from his predecessors? What enabled him to unite all of the Mongol tribes?
6. What was the significance of Inju to the history of the Chagatai Khanate?
7. What role did religion play in the Ilkhanate?
8. Why did Timur attempt to externalize the violence of the steppe?
9. Has Central Asia been an interesting stew of foreign influences, or has it been the product of internal forces?
10. Should the modern day states of Afghanistan and Iran be considered a part of Central Asia? Going back to the Mongol conquest of the region, what similarities do these states share with the core of Central Asia? What are some of the differences?
11. Should the conflict that has existed between nomadic and sedentary societies be considered the primary force determining the course of Central Asian history?
12. What has been the legacy of the conquests of Central Asia? How have the various empires shaped the region since the Turkic migrations?


6.3: Formal Charge and Resonance
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- Compute formal charges for atoms in any Lewis structure
- Use formal charges to identify the most reasonable Lewis structure for a given molecule
- Explain the concept of resonance and draw Lewis structures representing resonance forms for a given molecule
- Describe the energetics of covalent and ionic bond formation and breakage
- Use the Born-Haber cycle to compute lattice energies for ionic compounds
- Use average covalent bond energies to estimate enthalpies of reaction
Formal Charge
Previously, we discussed how to write Lewis structures for molecules and polyatomic ions. In some cases, however, there is seemingly more than one valid structure for a molecule. We can use the concept of formal charges to help us predict the most appropriate Lewis structure when more than one is reasonable.
Calculating Formal Charge
The formal charge of an atom in a molecule is the hypothetical charge the atom would have if we could redistribute the electrons in the bonds evenly between the atoms. Another way of saying this is that formal charge results when we take the number of valence electrons of a neutral atom, subtract the nonbonding electrons, and then subtract the number of bonds connected to that atom in the Lewis structure.
Thus, we calculate formal charge of an atom as follows:
\[\textrm{formal charge = # valence shell electrons (free atom) − # lone pair electrons − # bonds} \nonumber \]
We can double-check formal charge calculations by determining the sum of the formal charges for the whole structure. The sum of the formal charges of all atoms in a molecule must be equal to the charge of the molecule or ion.
We must remember that the formal charge calculated for an atom is not the actual charge of the atom in the molecule. Formal charge is only a useful bookkeeping procedure; it does not indicate the presence of actual charges.
Assign formal charges to each atom in the ion \(\ce{ICl4-}\).
S olution
We divide the bonding electron pairs equally for all \(\ce{I–Cl}\) bonds:
We assign lone pairs of electrons to their atoms. Each Cl atom now has seven electrons assigned to it, and the I atom has eight.
Subtract this number from the number of valence electrons for the neutral atom:
- I: 7 – 8 = –1
- Cl: 7 – 7 = 0
The sum of the formal charges of all the atoms equals –1, which is identical to the charge of the ion (–1).
Calculate the formal charge for each atom in the carbon monoxide molecule:
- Answer
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C −1, O +1
Assign formal charges to each atom in the interhalogen molecule \(\ce{BrCl3}\).
Solution
Assign one of the electrons in each Br–Cl bond to the Br atom and one to the Cl atom in that bond:
Assign the lone pairs to their atom. Now each Cl atom has seven electrons and the Br atom has seven electrons.
Subtract this number from the number of valence electrons for the neutral atom. This gives the formal charge:
- Br: 7 – 7 = 0
- Cl: 7 – 7 = 0
All atoms in \(\ce{BrCl3}\) have a formal charge of zero, and the sum of the formal charges totals zero, as it must in a neutral molecule.
Determine the formal charge for each atom in \(\ce{NCl3}\).
- Answer
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N: 0; all three Cl atoms: 0
Using Formal Charge to Predict Molecular Structure
The arrangement of atoms in a molecule or ion is called its molecular structure . In many cases, following the steps for writing Lewis structures may lead to more than one possible molecular structure—different multiple bond and lone-pair electron placements or different arrangements of atoms, for instance. A few guidelines involving formal charge can be helpful in deciding which of the possible structures is most likely for a particular molecule or ion.
- A molecular structure in which all formal charges are zero is preferable to one in which some formal charges are not zero.
- If the Lewis structure must have nonzero formal charges, the arrangement with the smallest nonzero formal charges is preferable.
- Lewis structures are preferable when adjacent formal charges are zero or of the opposite sign.
- When we must choose among several Lewis structures with similar distributions of formal charges, the structure with the negative formal charges on the more electronegative atoms is preferable.
To see how these guidelines apply, let us consider some possible structures for carbon dioxide, \(\ce{CO2}\). We know from our previous discussion that the less electronegative atom typically occupies the central position, but formal charges allow us to understand why this occurs. We can draw three possibilities for the structure: carbon in the center and double bonds, carbon in the center with a single and triple bond, and oxygen in the center with double bonds:
Comparing the three formal charges, we can definitively identify the structure on the left as preferable because it has only formal charges of zero (Guideline 1). The other two structures both have formal charges on two of the atoms.
As another example, the thiocyanate ion, an ion formed from a carbon atom, a nitrogen atom, and a sulfur atom, could have three different molecular structures: \(\ce{CNS^{–}}\), \(\ce{NCS^{–}}\), or \(\ce{CSN^{–}}\). The formal charges present in each of these molecular structures can help us pick the most likely arrangement of atoms. Possible Lewis structures and the formal charges for each of the three possible structures for the thiocyanate ion are shown here:
Note that the sum of the formal charges in each case is equal to the charge of the ion (–1). However, the first arrangement of atoms is preferred because it has the lowest number of atoms with nonzero formal charges (Guideline 2). Also, it places the least electronegative atom in the center, and the negative charge on the more electronegative element (Guideline 4).
Nitrous oxide, N 2 O, commonly known as laughing gas, is used as an anesthetic in minor surgeries, such as the routine extraction of wisdom teeth. Which is the likely structure for nitrous oxide?
Solution Determining formal charge yields the following:
The structure with a terminal oxygen atom best satisfies the criteria for the most stable distribution of formal charge:
The number of atoms with formal charges are minimized (Guideline 2), and there is no formal charge larger than one (Guideline 2). This is again consistent with the preference for having the less electronegative atom in the central position.
Which is the most likely molecular structure for the nitrite (\(\ce{NO2-}\)) ion?
- Answer
-
\(\ce{ONO^{–}}\)
Resonance
You may have noticed that the nitrite anion in Example \(\PageIndex{3}\) can have two possible structures with the atoms in the same positions. The electrons involved in the N–O double bond, however, are in different positions:
If nitrite ions do indeed contain a single and a double bond, we would expect for the two bond lengths to be different. A double bond between two atoms is shorter (and stronger) than a single bond between the same two atoms. Experiments show, however, that both N–O bonds in \(\ce{NO2-}\) have the same strength and length, and are identical in all other properties.
It is not possible to write a single Lewis structure for \(\ce{NO2-}\) in which nitrogen has an octet and both bonds are equivalent. Instead, we use the concept of resonance : if two or more Lewis structures with the same arrangement of atoms can be written for a molecule or ion, the actual distribution of electrons is an average of that shown by the various Lewis structures. The actual distribution of electrons in each of the nitrogen-oxygen bonds in \(\ce{NO2-}\) is the average of a double bond and a single bond. We call the individual Lewis structures resonance forms . The actual electronic structure of the molecule (the average of the resonance forms) is called a resonance hybrid of the individual resonance forms. A double-headed arrow between Lewis structures indicates that they are resonance forms. Thus, the electronic structure of the \(\ce{NO2-}\) ion is shown as:
We should remember that a molecule described as a resonance hybrid never possesses an electronic structure described by either resonance form. It does not fluctuate between resonance forms; rather, the actual electronic structure is always the average of that shown by all resonance forms. George Wheland, one of the pioneers of resonance theory, used a historical analogy to describe the relationship between resonance forms and resonance hybrids. A medieval traveler, having never before seen a rhinoceros, described it as a hybrid of a dragon and a unicorn because it had many properties in common with both. Just as a rhinoceros is neither a dragon sometimes nor a unicorn at other times, a resonance hybrid is neither of its resonance forms at any given time. Like a rhinoceros, it is a real entity that experimental evidence has shown to exist. It has some characteristics in common with its resonance forms, but the resonance forms themselves are convenient, imaginary images (like the unicorn and the dragon).
The carbonate anion, \(\ce{CO3^2-}\), provides a second example of resonance:
One oxygen atom must have a double bond to carbon to complete the octet on the central atom. All oxygen atoms, however, are equivalent, and the double bond could form from any one of the three atoms. This gives rise to three resonance forms of the carbonate ion. Because we can write three identical resonance structures, we know that the actual arrangement of electrons in the carbonate ion is the average of the three structures. Again, experiments show that all three C–O bonds are exactly the same.
Bond Length
Table \(\PageIndex{2}\) shows average bond lengths for some common covalent bonds with carbon, nitrogen, and oxygen.
| C | N | O | |
|---|---|---|---|
| C |
154 (C-C)
134 (C=C) 120 (C≡C) |
143 (C-N)
138 (C=N) 116 (C≡N) |
143 (C-O)
123(C=O) 113(C≡O) |
Summary
In a Lewis structure, formal charges can be assigned to each atom by treating each bond as if one-half of the electrons are assigned to each atom.  A structure in which the formal charges are as close to zero as possible is preferred. Resonance occurs in cases where two or more Lewis structures with identical arrangements of atoms but different distributions of electrons can be written. The actual distribution of electrons (the resonance hybrid) is an average of the distribution indicated by the individual Lewis structures (the resonance forms).
The strength of a covalent bond is measured by its bond dissociation energy, that is, the amount of energy required to break that particular bond in a mole of molecules. Multiple bonds are stronger than single bonds between the same atoms. The enthalpy of a reaction can be estimated based on the energy input required to break bonds and the energy released when new bonds are formed. For ionic bonds, the lattice energy is the energy required to separate one mole of a compound into its gas phase ions. Lattice energy increases for ions with higher charges and shorter distances between ions. Lattice energies are often calculated using the Born-Haber cycle, a thermochemical cycle including all of the energetic steps involved in converting elements into an ionic compound.
Key Equations
- Bond energy for a diatomic molecule: \(\ce{XY}(g)⟶\ce{X}(g)+\ce{Y}(g)\hspace{20px}\ce{D_{X–Y}}=ΔH°\)
- Enthalpy change: Δ H = ƩD bonds broken – ƩD bonds formed
- Lattice energy for a solid MX: \(\ce{MX}(s)⟶\ce M^{n+}(g)+\ce X^{n−}(g)\hspace{20px}ΔH_\ce{lattice}\)
- Lattice energy for an ionic crystal: \(ΔH_\ce{lattice}=\mathrm{\dfrac{C(Z^+)(Z^-)}{R_o}}\)
- \(\textrm{formal charge = # valence shell electrons (free atom) − # one pair electrons − }\dfrac{1}{2}\textrm{ # bonding electrons}\)
Glossary
- bond energy
- (also, bond dissociation energy) energy required to break a covalent bond in a gaseous substance.
- formal charge
- charge that would result on an atom by taking the number of valence electrons on the neutral atom and subtracting the nonbonding electrons and the number of bonds (one-half of the bonding electrons)
- lattice energy (Δ H lattice )
- energy required to separate one mole of an ionic solid into its component gaseous ions
- molecular structure
- arrangement of atoms in a molecule or ion
- resonance
- situation in which one Lewis structure is insufficient to describe the bonding in a molecule and the average of multiple structures is observed
- resonance forms
- two or more Lewis structures that have the same arrangement of atoms but different arrangements of electrons
- resonance hybrid
- average of the resonance forms shown by the individual Lewis structures
Contributors and Attributions
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Paul Flowers (University of North Carolina - Pembroke), Klaus Theopold (University of Delaware) and Richard Langley (Stephen F. Austin State University) with contributing authors. Textbook content produced by OpenStax College is licensed under a Creative Commons Attribution License 4.0 license. Download for free at<EMAIL_ADDRESS>).


3.7: Conservation of Mass - There is No New Matter
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It may seem as though burning destroys matter, but the same amount, or mass, of matter still exists after a campfire as before. Look at Figure \(\PageIndex{1}\) below. It shows that when wood burns, it combines with oxygen and changes not only to ashes, but also to carbon dioxide and water vapor. The gases float off into the air, leaving behind just the ashes. Suppose you had measured the mass of the wood before it burned and the mass of the ashes after it burned. Also suppose you had been able to measure the oxygen used by the fire and the gases produced by the fire. What would you find? The total mass of matter after the fire would be the same as the total mass of matter before the fire.
Law of Conservation of Mass
The law of conservation of mass was created in 1789 by a French chemist, Antoine Lavoisier. The law of conservation of mass states that matter cannot be created or destroyed in a chemical reaction. For example, when wood burns, the mass of the soot, ashes, and gases equals the original mass of the charcoal and the oxygen when it first reacted. So the mass of the product equals the mass of the reactant. A reactant is the chemical reaction of two or more elements to make a new substance, and a product is the substance that is formed as the result of a chemical reaction (Video \(\PageIndex{1}\)). Matter and its corresponding mass may not be able to be created or destroyed, but can change forms to other substances like liquids, gases, and solids.
If you witness a 300 kg tree burn to the ground, there are only ashes left after the burn, and all of them together weigh 10 kg. It may make you wonder where the other 290 kg went. The missing 290 kg was released into the atmosphere as smoke, so the only thing left that you can see is the 10 kg of ash. If you know the law of conservation of mass, then you know that the other 290 kg has to go somewhere, because it has to equal the mass of the tree before it burnt down.
Example \(\PageIndex{1}\)
If heating 10.0 grams of calcium carbonate (CaCO 3 ) produces 4.4 g of carbon dioxide (CO 2 ) and 5.6 g of calcium oxide (CaO), show that these observations are in agreement with the law of conservation of mass.
Solution
\[\begin{align*} \text{Mass of the reactants} &= \text{Mass of the products} \\[4pt] 10.0\, \text{g of } \ce{CaCO3} &= 4.4 \,\text{g of }\ce{CO2} + 5.6\, \text{g of } \ce{ CaO} \\[4pt] 10.0\,\text{g of reactant} &= 10.0\, \text{g of products} \end{align*} \nonumber \]
Because the mass of the reactant is equal to the mass of the products, the observations are in agreement with the law of conservation of mass.
Exercise \(\PageIndex{1}\)
Potassium hydroxide (\(\ce{KOH}\)) readily reacts with carbon dioxide (\(\ce{CO2}\)) to produce potassium carbonate (\(\ce{K2CO3}\)) and water (\(\ce{H2O}\)). How many grams of potassium carbonate are produced if 224.4 g of \(\ce{KOH}\) reacts with 88.0 g of \(\ce{CO2}\)? The reaction also produces 36.0 g of water.
- Answer
- 276.4 g of potassium carbonate
The Law is also applicable to both chemical and physical changes. For example, if you have an ice cube that melts into a liquid and you heat that liquid up, it becomes a gas. It will appear to have disappeared, but is still there.
Summary
- Burning and other changes in matter do not destroy matter.
- The mass of matter is always the same before and after the changes occur.
- The law of conservation of mass states that matter cannot be created or destroyed.


Chromium
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Learning Objectives
The functioning of chromium in the body is less understood than that of most other minerals. It enhances the actions of insulin so plays a role in carbohydrate, fat, and protein metabolism. Currently, the results of scientific studies evaluating the usefulness of chromium supplementation in preventing and treating Type 2 diabetes are largely inconclusive. More research is needed to better determine if chromium is helpful in treating certain chronic diseases and, if so, at what doses. Dietary sources of chromium include nuts, whole grains, and yeast. The recommended intake for chromium is 35 mcg per day for adult males and 25 mcg per day for adult females. There is insufficient evidence to establish an UL for chromium.
University of Hawai’i at Mānoa Food Science and Human Nutrition Program : Allison Calabrese, Cheryl Gibby, Billy Meinke, Marie Kainoa Fialkowski Revilla, and Alan Titchenal


2.1.4: Chapter Summary
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- Tom Buckley
- University of California, Davis
A cell i s the smallest unit of a living thing. Whether comprised of one cell (like bacteria) or many cells (like a plant), we call it an organism.  Eukaryotic cells are generally around 10 to 100 μm in size. As a cell increases in size, its surface area-to-volume ratio decreases, decreasing the efficiency of transport. If the cell grows too large, the plasma membrane will not have sufficient surface area to support the rate of diffusion required for the increased volume. All cells contain these same four components: 1. plasma (cell) membrane , 2. cytoplasm and the fluid region, cytosol , 3. DNA, and 4. ribosomes . Eukaryotic cells contain organelles and a membrane-bound nucleus that is attached to an endomembrane system. The main structures that comprise the endomembrane system are the endoplasmic reticulum , vesicles , and the Golgi body . Furthermore, eukaryotic cells contain cytoskeleton and a mitochondria . Plant cells contain some structures animal cells don't possess: a cell wall , central vacuole , peroxisomes , and plastids , most notably chloroplasts . The mitochondria and chloroplast have evolved via the Endosymbiosis Theory .
Several plant cells of one kind that interconnect with each other and perform a shared function form tissues. Plant tissue systems fall into one of two general types: meristematic tissue , and permanent (or non-meristematic) tissue. Dermal tissue covers the plant and can be found on the outer layer of roots, stems and leaves. Vascular tissue is the plumbing system of the plant. It allows water, minerals, and dissolved sugars from photosynthesis to pass through roots, stems, leaves, and other parts of the plant. It is primary composed of two types of conducting tissue: xylem and phloem . Tissues that are not considered dermal or vascular tissue are noted as ground tissue . These cells store molecules (such as starch), photosynthesize (such as mesophyll cells), or support the plant. Ground tissue is often divided into three cell types: collenchyma , sclerenchyma , and parenchyma .
After completing this chapter, you should be able to...
- Describe the role of cells in organisms.
- Summarize cell theory.
- Address the significance of cell size.
- Describe the structures that all cells share in common.
- State the role of the plasma membrane.
- Describe the structures of eukaryotic cells.
- Summarize the functions of the major cell organelles.
- Describe the difference between meristematic and non-meristematic tissues.
- Compare and contrast dermal, ground, and vascular tissue.
Attribution
Curated and authored by Kammy Algiers using 4.1 Studying Cells and 4.3 Eukaryotic cells from Biology 2e by OpenStax (licensed CC-BY ). Access for free at openstax.org .


6.4: Fundamental Theorem of Calculus
In the previous two sections, we saw that the area under a curve can be found using more and more rectangles. However, this process can be tedious and not very enlightening. There is a powerful theorem that allows us to compute area under the curve quickly in many cases.
Given a function \(f(x)\) where \(F(x)\) is an anti-derivative of \(f(x)\), we have
\(\int_a^b f(x)dx = F(b) - F(a)\)
This is a really remarkable theorem. At first blush, finding the area under a curve and finding the slope of a tangent line have nothing in common. What this theorem is saying is that these are intimately tied, and in fact that are exactly inverse operations. That is, one undoes the other. Moreover, this gives an exact answer to integral problems, something that eluded us in the previous sections.
For example, let’s say we wanted to solve the following:
To use the fundamental theorem, we need an anti-derivative of \(f(x) = x^2\). The anti-derivative in this case, by the inverse power rule, is \(F(b) - F(a)\), which is
\[\begin{align*} \int_2^5 x^2dx & = \frac{5^3}{3} - \frac{2^3}{3} \\ & = \frac{125}{3} - \frac{8}{3} \\ & = \frac{117}{3} \\ & = \boxed{39} \end{align*}\]
The area under the curve is \(39\). Note that \(F(b) - F(a)\) is sometimes denoted \(F(x) \Big|_a^b.\) We’ll see that in the following examples.
-
Find \(\int_{-2}^1 3x^2dx\).
To solve this, we find the anti-derivative of \(3x^2\), and then plug in the end points and subtract the result. First note that \(\int 3x^2dx = x^3 + C\).
\[\begin{align*} \int_{-2}^1 3x^2dx & = x^3 + C \Big|_{-2}^1 \\ & = (1^3 + C) - ((-2)^3 + C) \\ & = 1 + C - (-8 + C) \\ & = 1 + C + 8 - C \\ & = \boxed{9} \end{align*}\]
Notice how the constants of integration cancel? For definite integral problems, we can essentially ignore the constant of integration for this reason.
-
Find \(\int_0^6 \frac{1}{2}x^2 + \frac{1}{3} xdx\).
We integrate and then evaluate again.
\[\begin{align*} \int_0^6 \frac{1}{2}x^2 + \frac{1}{3} xdx & = \frac{1}{2} \int_0^6 x^2 + \frac{1}{3} \int_0^6 xdx \\ & = \left( \frac{1}{2} \frac{x^3}{3} + \frac{1}{3} \frac{x^2}{2} \right) \Big|_0^6 \\ & = \left( \frac{x^3}{6} + \frac{x^2}{6} \right) \Big|_0^6 \\ & = \frac{x^3 + x^2}{6} \Big|_0^6 \\ & = \left( \frac{6^3 + 6^2}{6} \right) - \left( \frac{0^3 + 0^2}{6} \right) \\ & = \frac{252}{6} - \frac{0}{6} \\ & = \boxed{42}. \end{align*}\]
Why does the fundamental theorem of calculus work? As we have seen earlier, it is sometimes easiest to see in terms of position versus velocity. Let \(F(x)\) be the position function of a car, let \(f(x)\) be the velocity function of the car, and let \(x\) be the time in hours. For simplicity, let’s say \(f(x)\) is constant from \(x = 2\) to \(x = 6\):
So if this is the velocity function, what is happening to the position function? As we’ve seen, we just need to multiply : its the \(10 \frac{\text{miles}}{\text{hour}}\) times the four hours, gives a change of 40 miles. That means \(F(x)\) looks something like this:
Note it need not start at \(5\) miles, but that is one possibility.
Now let’s look at the fundamental theorem again:
Given a function \(f(x)\) where \(F(x)\) is an anti-derivative of \(f(x)\), we have
\(\int_a^b f(x)dx = F(b) - F(a)\)
Can you see why the fundamental theorem worked out in this case? We see see \(F(b) - F(a)\) is just the change of position between hour \(2\) and hour \(6\), which is \(45-5\) or \(40\) miles. What is \(\int_a^b f(x)dx\)? Well, that’s the area under the velocity curve. How do you find area? That’s right, it’s multiplication ! In particular, it is \(10 \frac{\text{miles}}{\text{hour}}\) times the four hours, again giving a change of \(40\) miles.
You can see how both area under the curve and antiderivatives come down to the same basic calculation. That’s why the fundamental theorem of calculus can claim they are the same thing.
If the velocity function is more complicated, this still works. We can think of a more complicated function as a combination of these constant functions.


13.3: Galaxies
A galaxy is a massive, gravitationally bound system of stars, stellar remnants, interstellar medium, and dark matter. The term galaxy comes from the Greek galaxias, literally translated as milk or milky, referring to our Milky Way galaxy. Galaxies can range in size from the dwarf galaxies — as small as ten million stars, to giant galaxies with one hundred trillion stars. It is currently estimated that there are 170 billion galaxies in the Universe. It is believed that nearly all galaxies also contain stellar systems with planets orbiting many of their stars, like our Milky Way galaxy. However, that has not been confirmed, but is a solid theory based on what we have discovered in the Milky Way, and comparing the characteristics of the Milky Way to other galaxies.
A number of galaxies are believed to have supermassive black holes at their centers. The Milky Way’s supermassive black hole is called Sagittarius A * or SGR A * . These supermassive black holes have been observed in a number of other galaxies; astronomers are trying to determine if this is a consistent characteristic.
These supermassive black holes are hypothesized to be the principal driver of the active galactic nuclei or AGN . An AGN is a compact region located at a galaxy’s center, which has a significantly higher luminosity from one to several ranges of the electromagnetic spectrum.


1.13: Joseph de Maistre — Excerpts from Study on Sovereignty, 1794
Joseph de Maistre was a French writer, philosopher, and diplomat. Caught up in the turmoil and chaos of the French Revolution in 1789, de Maistre turned to conservative ideas of monarchy and hierarchy.
ON THE ORIGINS OF SOVEREIGNTY
…society is not the work of man, but the immediate result of the will of the Creator who has willed that man should be what he has always and everywhere been.
…SOVEREIGNTY IN GENERAL
…If sovereignty is not anterior to the people, at least these two ideas are collateral, since a sovereign is necessary to make a people. It is as impossible to imagine a human society, a people, without a sovereign as a hive and bees without a queen: for, by virtue of the eternal laws of nature, a swarm of bees exists in this way or it does not exist at all. Society and sovereignty are thus born together; it is impossible to separate these two ideas. Imagine an isolated man: there is no question of laws or government, since he is not a whole man and society does not yet exist. Put this man in contact with his fellowmen: from this moment you suppose a sovereign. The first man was king over his children; each isolated family was governed in the same way. But once these families joined, a sovereign was needed, and this sovereign made a people of them by giving them laws, since society exists only through the sovereign. Everyone knows the famous line,
The first king was a fortunate soldier.
This is perhaps one of the falsest claims that has ever been made. Quite the opposite could be said, that
The first soldier was paid by a king.
There was a people, some sort of civilization, and a sovereign as soon as men came into contact. The word people is a relative term that has no meaning divorced from the idea of sovereignty: for the idea of a people involves that of an aggregation around a common center, and without sovereignty there can be no political unity or cohesion…
…PARTICULAR SOVEREIGNTIES AND NATIONS
…The same power that has decreed social order and sovereignty has also decreed different modifications of sovereignty according to the different character of nations. Nations are born and die like individuals. Nations have fathers, in a very literal sense, and teachers commonly more famous than their fathers, although the greatest merit of these teachers is to penetrate the character of the infant nation and to create for it circumstances in which it can develop all its capacities.
Nations have a general soul and a true moral unity which makes them what they are. This unity is evidenced above all by language.
The Creator has traced on the globe the limits of nations…These boundaries are obvious and each nation can still be seen straining to fill entirely one of the areas within these boundaries. Sometimes invincible circumstances thrust two nations together and force them to mingle. Then their constituent principles penetrate each other and produce a hybrid nation which can be either more or less powerful and famous than if it was a pure race.
But several national elements thrown together into the same receptacle can be harmful. These seeds squeeze and stifle each other. The men who compose them, condemned to a certain moral and political mediocrity, will never attract the eyes of the world in spite of a large number of individual virtues, until some great shock, starting one of these seeds growing, allows it to engulf the other and to assimilate them into its own substance. Italiam! Italiam!
Sometimes a nation lives in the midst of another much more numerous, refuses to integrate because there is not sufficient affinity between them, and preserves its moral unity….
When one talks of the spirit of a nation, the expression is not so metaphorical as is believed.
From these different national characteristics are born the different modifications of governments. One can say that each government has its separate character, for even those which belong to the same group and carry the same name reveal subtle differences to the observer.
The same laws cannot suit different provinces which have different customs, live in opposite climates, and cannot accept the same form of government.
The general objects of every good institution must be modified in each country by the relationships which spring as much from the local situation as from the character of the inhabitants. It is on the basis of these relationships that each people should be assigned a particular institutional system, which is the best, not perhaps in itself, but for the state for which it is intended.
There is only one good government for a particular state; yet not only can different governments be suitable for different peoples; they can also be suitable for the same people at different times, since a thousand events can change the inner relationships of a people.
There has always been a great deal of discussion on the best form of government without consideration of the fact that each can be the best in some instances and the worst in others!
Therefore it should not be said that every form of government is appropriate to every country: for example, liberty, since it will not grow under every climate, is not open to every nation. The more one thinks about this principle laid down by Montesquieu, the more one feels its force. The more it is contested, the more strongly it is established by new proofs. Thus the absolute question, What is the best form of government? is as insoluble as it is indefinite; or, to put it another way, it has as many correct solutions as there are possible combinations in the relative and absolute positions of nations.
…THE FOUNDERS AND THE POLITICAL CONSTITUTION OF NATIONS
…Thinking about the moral unity of nations, there can be no doubt that it is the result of a single cause. What the wise Bonnet said about the animal body in answer to a fancy of Buffon can be said about the body politic: every seed is necessarily one; and it is always from a single man that each nation takes its dominant trait and its distinctive character.
To know, then, why and how a man literally engenders a nation, and how he passes on to them the moral temperament, the character, the general soul which must, over the course of centuries and an infinite number of generations, exist perceptibly and distinguish one nation from all others, this is a mystery like so many others on which it is fruitful to dwell…. The government of a nation is no more its own work than its language. Just as in nature the seeds of an infinite number of plants are destined to perish unless the wind or the hand of man puts them where they can germinate, so also there are in nations certain qualities and powers which are ineffective until they get a stimulus from circumstances either alone or used by a skillful hand.
…The founder of a nation is precisely this skillful hand. Gifted with an extraordinary penetration or, what is more probable, with an infallible instinct (for often personal genius does not realize what it is achieving, which is what distinguishes it above all from intelligence), he divines those hidden powers and qualities which shape a nation’s character, the means of bringing them to life, putting them into action, and making the greatest possible use of them. He is never to be seen writing or debating; his mode of acting derives from inspiration; and if sometimes he takes up a pen, it is not to argue but to command.
One of the greatest errors of this age is to believe that the political constitution oœ nations is the work of man alone and that a constitution can be made as a watchmaker makes a watch. This is quite false; but still more false is the belief that this great work can be executed by an assembly of men. The author of all things has only two ways of giving a government to a people. Most often he reserves to himself its formation more directly by making it grow, as it were, imperceptibly like a plant, through the conjunction of a multitude of those circumstances we call fortuitous. But when he wants to lay quickly the foundations of a political structure and to show the world a creation of this kind, he confides his power to rare men, the true Elect. Scattered thinly over the centuries, they rise like obelisks on time’s path, and, as humanity grows older, they appear the less. To fit them for these unusual tasks, God invests them with unusual power, often unknown to their contemporaries and perhaps to themselves. Bousseau himself has spoken the truth when he said that the work of the founder of a nation was a MISSION…. If the founders of nations, who were all prodigious men, were to come before our eyes and we were to recognize their genius and their power, instead of talking nonsensically of usurpation, fraud, and fanaticism, we would fall on our knees and our sterility would disappear before the sacred sign shining from their brows….
What is certain is that the constitution of a nation is never the product of deliberation.
Almost all the great legislators have been kings, and even those nations destined to be republics have been constituted by kings. They are the men who preside at the political establishment of nations and draw up their first fundamental laws….
Look at every one of the world’s constitutions, ancient and modern: you will see that now and again long experience has been able to point out some institutions capable of improving governments on the basis of their original constitution or of preventing abuses capable of altering their nature. It is possible to name the date and authors of these institutions, but you will notice that the real roots of government have remained the same and that it is impossible to show their origin, for the very simple reason that they are as old as the nations and that, not being the result of an agreement, there can be no trace of a convention which never existed.
…All known nations have been happy and powerful to the degree that they have faithfully obeyed this national mind, which is nothing other than the destruction of individual dogmas and the absolute and general rule of national dogmas, that is to say, useful prejudices. Once let everyone rely on his individual reason in religion, and you will see immediately the rise of anarchy of belief or the annihilation of religious sovereignty. Likewise, if each man makes himself the judge of the principles of government you will see immediately the rise of civil anarchy or the annihilation of political sovereignty. Government is a true religion; it has its dogmas, its mysteries, its priests; to submit it to individual discussion is to destroy it; it has life only through the national mind, that is to say, political faith, which is a creed. Man’s primary need is that his nascent reason should be curbed under a double yoke; it should be frustrated, and it should lose itself in the national mind, so that it changes its individual existence for another communal existence, just as a river which flows into the ocean still exists in the mass of water, but without name and distinct reality.
…What is patriotism? It is this national mind of which I am speaking; it is individual abnegation. Faith and patriotism are the two great thaumaturges of the world. Both are divine. All their actions are miracles. Do not talk to them of scrutiny, choice, discussion, for they will say that you blaspheme. They know only two words, submission and belief; with these two levers, they raise the world. Their very errors are sublime. These two infants of Heaven prove their origin to all by creating and conserving; and if they unite, join their forces and together take possession of a nation, they exalt it, make it divine and increase its power a hundredfold….
…MONARCHY
…It can be said in general that all men are born for monarchy. This form of government is the most ancient and the most universal….Monarchical government is so natural that, without realizing it, men identify it with sovereignty. They seem tacitly to agree that, wherever there is no king, there is no real sovereign….
Image Attribution: “Joseph de Maistre” by Carl Christian Vogel von Vogelstein , Wikimedia Commons is in the Public Domain


One very influential approach in understanding human development is the evolutionary perspective, the final developmental perspective that we will consider. This perspective seeks to identify behavior that is the result of our genetic inheritance from our ancestors.
Evolutionary psychology
is a theoretical approach in the social and natural sciences that examines psychological structure from a modern evolutionary perspective. It seeks to identify which human psychological traits are evolved adaptations – that is, the functional products of natural selection or sexual selection in human evolution.
David M. Buss is an evolutionary psychologist at the University of Texas at Austin, theorizing and researching human sex differences in mate selection. The primary topics of his research include male mating strategies, conflict between the sexes, social status, social reputation, prestige, the emotion of jealousy, homicide, anti-homicide defenses, and—most recently—stalking. All of these are approached from an evolutionary perspective.
Evolutionary psychology has its historical roots in Charles Darwin’s theory of natural selection. In
The Origin of Species
, Darwin predicted that psychology would develop an evolutionary basis, and
that a process of natural selection creates traits in a species that are adaptive to its environment.
Using Darwin’s arguments, evolutionary approaches
claim that one’s genetic inheritance not only determine such physical traits as skin and eye color, but also certain personality traits and social behaviors. For example, some evolutionary developmental psychologists suggest that behavior such as shyness and jealousy may be produced in part by genetic causes, presumably because they helped increase the survival rates of human’s ancient relatives.
[1]
[2]
[3]
Lorenz and Imprinting
The evolutionary perspective draws heavily on the field of
ethology
, which examines the ways in which our biological makeup influences our behavior.
The primary proponent of ethology was Konrad Lorenz, who discovered that newborn geese are genetically pre-programmed to become attached to the first moving object they see after birth.
Lorenz’s work led developmentalists to consider the ways in which human behavior might reflect inborn genetic patterns. Working with geese, he investigated the principle of imprinting
,
the process by which some nidifugous birds (i.e. birds that leave their nest early) bond instinctively with the first moving object that they see within the first hours of hatching. Although Lorenz did not discover the topic, he became widely known for his descriptions of imprinting as an instinctive bond.
In psychology and ethology,
imprinting
is any kind of phase-sensitive learning (learning occurring at a particular age or a particular life stage) that is rapid and apparently independent of the consequences of behavior. It was first used to describe situations in which an animal or person learns the characteristics of some stimulus, which is therefore said to be “imprinted” onto the subject. Imprinting is hypothesized to have a critical period.
Behavioral Genetics
The evolutionary perspective encompasses one of the fastest-growing areas within the field of lifespan development: behavioral genetics.
Behavioral genetics
is a field of scientific research that uses genetic methods to investigate the nature and origins of individual differences in behavior and studies the effects of heredity on behavior. Behavioral geneticists strive to understand how we might inherit certain behavioral traits and how the environment influences whether we actually displayed those traits. It also considers how genetic factors may influence psychological disorders such as schizophrenia, depression and substance abuse.
[4]
[5]
[6]
Link to Learning
In Stanford professor and author of
Why Zebras Don’t Get Ulcers
,
Robert Sapolsky’s Ted Talk
, Sapolsky describes how our history and biology influence our behavior. This tour of our individual and collective history provides an enlightening overview of behavioral genetics.
Criticisms of the Evolutionary Perspective
There is a general acceptance that Darwin’s evolutionary theory provides an accurate description of basic genetic processes and that the evolutionary perspective is increasingly visible in the field of lifespan development. However, applications of the evolutionary perspective have been subjected to considerable criticism. Some developmental psychologists are concerned over too much emphasis on genetic and biological aspects of behavior and suggest that the evolutionary perspective places insufficient attention on environmental and social factors involved in producing children’s and adults behavior. Other critics argue that there is no good way to experimentally test theories derived from this approach because humans evolved so long ago. For example, we may admit that jealousy helps individuals to survive more effectively, but how do we prove it. All things considered however, the evolutionary approach is continually stimulating research on how our biological inheritance at least partially influences our traits and behaviors.
[7]
[8]
[9]
one of the fastest-growing areas within the field of lifespan development and studies the effects of heredity on behavior
ethology
the study of behavior through a biological lens
evolutionary psychology
a field of study that seeks to identify behavior that is a result of our genetic inheritance from our ancestors
imprinting
in psychology and ethology, imprinting is any kind of phase-sensitive learning (learning occurring at a particular age or a particular life stage) that is rapid and apparently independent of the consequences of behavior
Buss, A.H 2012 Pathways to individuality: evolution and development of personality traits. Washington, DC: American psychological Association
<EMAIL_ADDRESS>Easton, JM., Schipper, L., And Shackleford, T. 2007 morbid jealousy from an evolutionary psychological perspective. Evolution and human behavior, 28, 399 –402
<EMAIL_ADDRESS>Origins of the Social Mind: Evolutionary Psychology and Child Development, Bruce J. Ellis, David F. Bjorklund pp 3-18 New York Guilford Press, Jan 1, 2005
<EMAIL_ADDRESS>Rembis , M. 2009( re)defining disability in the “genetic age”: behavioral genetics, “new” eugenics and the future of impairment. Disability and society, 24, 585<EMAIL_ADDRESS>PLOMIN, R., DEFRIES, J. C. , KnOPIK, V. S., & NEIDERHISER, J. M. 2016. Top 10 replicated findings from behavioral genetics. Perspectives on psychological science, 11, 3–23.
<EMAIL_ADDRESS>Bjorklund, D. 2006 mother knows best, epigenetic inheritance, maternal effects, and the evolution of human intelligence. Developmental review, 26, 213 –242.
<EMAIL_ADDRESS>Baptista, T., Aldana, E., Angeles , F., And Beaulieu , S. 2008. Evolution theory: an overview of its applications in psychiatry. Psychopathology, 41, 17 –27.
<EMAIL_ADDRESS>Del Giudice, M. 2015. Self-regulation in an evolutionary perspective. In G. E. Gendolla, M. Tops, S. L. Koole, G. E. Gendolla, M. Tops, & S. L. Koole (Eds), Handbook of behavioral approaches to self-regulation. New York, New York: Springer science + business media
<EMAIL_ADDRESS>Contributors and Attributions
CC licensed content, Original
The Evolutionary Perspective : Genetic Inheritance from our Ancestors.
Authored by
: Sonja Ann Miller for Lumen Learning.
Provided by
: Lumen Learning.
License
:
CC BY-SA: Attribution-ShareAlike


11.6: The Ekman Spiral and Geostrophic Flow
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Ekman spiral
Winds blowing over the ocean are ultimately what create the surface currents. However, not all of the water moved by the surface currents is transported in the same direction. The Coriolis Effect causes the surface water to move in a direction about 45 degrees offset from the wind direction, with the deflection to the right of the wind in the Northern Hemisphere and to the left in the Southern Hemisphere. The frictional movement of the topmost layer of water sets in motion the layer directly underneath it, which then sets in motion the next layer under that, and so on as the water gets deeper. Some energy is lost in each transition, so each successive layer of water will not move as far as the layer above it; in other words, there is decreasing energy with increasing depth. But at the same time, the Coriolis Effect deflects each layer relative to the layer above it (again, to the right in the Northern Hemisphere and to the left in the Southern Hemisphere). The movement of the successive layers therefore creates a spiraling pattern of water motion called the Ekman spiral , which usually penetrates to about 100 m deep before the motion ceases. If the magnitudes and directions of the movements of each layer are added together, the result is that the net movement of the upper 100 m of the water column is 90 o relative to the original wind direction (90 o to the right of the wind in the Northern Hemisphere, and 90 o to the left in the Southern Hemisphere). This net water movement is called Ekman transport (Figure \(\PageIndex{1}\)).
Geostrophic flow
Gyre rotation is dependent on the wind and the Coriolis Effect impacting the surface currents (see section 9.1). But the rotation is also affected by movement below the surface due to Ekman transport. In the Northern Hemisphere, as the gyre rotates clockwise the net movement of the Ekman transport is 90 o to the right of the wind; in other words, towards the center of the gyre. The Ekman transport piles up water in the center of the gyre, making the water level higher in the gyre center than on the edges of the gyres. This pile of water then has a tendency to flow back “downhill” due to gravity. As the water flows “downhill” away from the gyre center, it is deflected to the right by the Coriolis force. This results in a clockwise current around the central “hill” called geostrophic flow , which moves in the same direction as the rotating gyre. Water is thus pushed into the “hill” by Ekman transport, and away from the “hill” by gravity, with both flows modified by the Coriolis Effect to create the rotation. As with the gyres, geostrophic flow is clockwise in the Northern Hemisphere, and counterclockwise in the Southern Hemisphere.
Most major surface currents are a combination of wind-driven and geostrophic currents. Since winds can be variable, geostrophic flow ensure that the gyre currents keep moving at a fairly constant rate even when the wind dies down. The larger the area, and the higher the slope, the longer the geostrophic flow will continue to move and power the gyre after the wind subsides.


13.2: The Pulitzer Prize
Despite the problems inherent in trying to identify the “best” music, we have long insisted on doing so. This is evidenced by countless competitions and awards across all genres of music. Perhaps the most prominent award given to a composer of art music is the Pulitzer Prize for Music, which has been awarded annually since 1943. The current criteria indicate that this award is “For a distinguished musical composition by an American that has had its first performance or recording in the United States during the year.” The history of Pulitzer Prize winners, therefore, should be a history of the best music composed in the last 75 years. In truth, of course, many of the composers and works to receive the Pulitzer have been forgotten, while many great musicians were never considered because their music was not considered to be art.


27.4: The Pacific Theater and the Atomic Bomb
Japanese forces won a series of early victories against Allied forces from December 1941 to May 1942. They seized Guam and Wake Island from the United States, and streamed through Malaysia and Thailand into the Philippines and through the Dutch East Indies. By February 1942, they were threatening Australia. The Allies turned the tide in May and June 1942, at the Battle of Coral Sea and the Battle of Midway. The Battle of Midway witnessed the first Japanese naval defeat since the nineteenth century. Shortly after the American victory, U.S. forces invaded Guadalcanal and New Guinea. Slowly, throughout 1943, the United States engaged in a campaign of “island hopping,” gradually moving across the Pacific to Japan. In 1944, the United States, seized Saipan and won the Battle of the Philippine Sea. Progressively, American forces drew closer to the strategically important targets of Iwo Jima and Okinawa.
THE PACIFIC CAMPAIGN
During the 1930s, Americans had caught glimpses of Japanese armies in action and grew increasingly sympathetic towards war-torn China. Stories of Japanese atrocities bordering on genocide and the shock of the attack on Pearl Harbor intensified racial animosity toward the Japanese. Wartime propaganda portrayed Japanese soldiers as uncivilized and barbaric, sometimes even inhuman (Figure 27.4.1), unlike America’s German foes. Admiral William Halsey spoke for many Americans when he urged them to “Kill Japs! Kill Japs! Kill more Japs!” Stories of the dispiriting defeats at Bataan and the Japanese capture of the Philippines at Corregidor in 1942 revealed the Japanese cruelty and mistreatment of Americans. The “Bataan Death March,” during which as many as 650 American and 10,000 Filipino prisoners of war died, intensified anti-Japanese feelings. Kamikaze attacks that took place towards the end of the war were regarded as proof of the irrationality of Japanese martial values and mindless loyalty to Emperor Hirohito.
Despite the Allies’ Europe First strategy, American forces took the resources that they could assemble and swung into action as quickly as they could to blunt the Japanese advance. Infuriated by stories of defeat at the hands of the allegedly racially inferior Japanese, many high-ranking American military leaders demanded that greater attention be paid to the Pacific campaign. Rather than simply wait for the invasion of France to begin, naval and army officers such as General Douglas MacArthur argued that American resources should be deployed in the Pacific to reclaim territory seized by Japan.
In the Pacific, MacArthur and the Allied forces pursued an island hopping strategy that bypassed certain island strongholds held by the Japanese that were of little or no strategic value. By seizing locations from which Japanese communications and transportation routes could be disrupted or destroyed, the Allies advanced towards Japan without engaging the thousands of Japanese stationed on garrisoned islands. The goal was to advance American air strength close enough to Japan proper to achieve air superiority over the home islands; the nation could then be bombed into submission or at least weakened in preparation for an amphibious assault. By February 1945, American forces had reached the island of Iwo Jima (Figure 27.4.2). Iwo Jima was originally meant to serve as a forward air base for fighter planes, providing cover for long-distance bombing raids on Japan. Two months later, an even larger engagement, the hardest fought and bloodiest battle of the Pacific theater, took place as American forces invaded Okinawa. The battle raged from April 1945 well into July 1945; the island was finally secured at the cost of seventeen thousand American soldiers killed and thirty-six thousand wounded. Japanese forces lost over 100,000 troops. Perhaps as many as 150,000 civilians perished as well.
DROPPING THE ATOMIC BOMB
All belligerents in World War II sought to develop powerful and devastating weaponry. As early as 1939, German scientists had discovered how to split uranium atoms, the technology that would ultimately allow for the creation of the atomic bomb. Albert Einstein, who had emigrated to the United States in 1933 to escape the Nazis, urged President Roosevelt to launch an American atomic research project, and Roosevelt agreed to do so, with reservations. In late 1941, the program received its code name: the Manhattan Project. Located at Los Alamos, New Mexico, the Manhattan Project ultimately employed 150,000 people and cost some $2 billion. In July 1945, the project’s scientists successfully tested the first atomic bomb.
In the spring of 1945, the military began to prepare for the possible use of an atomic bomb by choosing appropriate targets. Suspecting that the immediate bomb blast would extend over one mile and secondary effects would include fire damage, a compact city of significant military value with densely built frame buildings seemed to be the best target. Eventually, the city of Hiroshima, the headquarters of the Japanese Second Army, and the communications and supply hub for all of southern Japan, was chosen. The city of Kokura was chosen as the primary target of the second bomb, and Nagasaki, an industrial center producing war materiel and the largest seaport in southern Japan, was selected as a secondary target.
The Enola Gay , a B-29 bomber named after its pilot’s mother, dropped an atomic bomb known as “Little Boy” on Hiroshima at 8:15 a.m. Monday morning, August 6, 1945. A huge mushroom cloud rose above the city. Survivors sitting down for breakfast or preparing to go to school recalled seeing a bright light and then being blown across the room. The immense heat of the blast melted stone and metal, and ignited fires throughout the city.  A female survivor, a child at the time of the attack, remembered finding the body of her mother, which had been reduced to ashes and fell apart as she touched it. Two-thirds of the buildings in Hiroshima were destroyed. Within an hour after the bombing, radioactive “black rain” began to fall. Approximately seventy thousand people died in the original blast. The same number would later die of radiation poisoning. When Japan refused to surrender, a second atomic bomb, named Fat Man, was dropped on Nagasaki on August 9, 1945. At least sixty thousand people were killed at Nagasaki. Kokura, the primary target, had been shrouded in clouds on that morning and thus had escaped destruction. It is impossible to say with certainty how many died in the two attacks; the heat of the bomb blasts incinerated or vaporized many of the victims (Figure 27.4.3).
Visit the Atomic Bomb Museum site to read the accounts of survivors Hiroshi Morishita and Shizuko Nishimoto.
The decision to use nuclear weapons is widely debated. Why exactly did the United States deploy an atomic bomb? The fierce resistance that the Japanese forces mounted during their early campaigns led American planners to believe that any invasion of the Japanese home islands would be exceedingly bloody. According to some estimates, as many as 250,000 Americans might die in securing a final victory. Such considerations undoubtedly influenced President Truman’s decision. Truman, who had not known about the Manhattan Project until Roosevelt’s death, also may not have realized how truly destructive it was. Indeed, some of the scientists who had built the bomb were surprised by its power. One question that has not been fully answered is why the United States dropped the second bomb on Nagasaki. As some scholars have noted, if Truman’s intention was to eliminate the need for a home island invasion, he could have given Japan more time to respond after bombing Hiroshima. He did not, however. The second bombing may have been intended to send a message to Stalin, who was becoming intransigent regarding postwar Europe. If it is indeed true that Truman had political motivations for using the bombs, then the destruction of Nagasaki might have been the first salvo of the Cold War with the Soviet Union. And yet, other historians have pointed out that the war had unleashed such massive atrocities against civilians by all belligerents—the United States included—that by the summer of 1945, the president no longer needed any particular reason to use his entire nuclear arsenal.
THE WAR ENDS
Whatever the true reasons for their use, the bombs had the desired effect of getting Japan to surrender. Even before the atomic attacks, the conventional bombings of Japan, the defeat of its forces in the field, and the entry of the Soviet Union into the war had convinced the Imperial Council that they had to end the war. They had hoped to negotiate the terms of the peace, but Emperor Hirohito intervened after the destruction of Nagasaki and accepted unconditional surrender. Although many Japanese shuddered at the humiliation of defeat, most were relieved that the war was over. Japan’s industries and cities had been thoroughly destroyed, and the immediate future looked bleak as they awaited their fate at the hands of the American occupation forces.
The victors had yet another nation to rebuild and reform, but the war was finally over. Following the surrender, the Japanese colony of Korea was divided along the thirty-eighth parallel; the Soviet Union was given control of the northern half and the United States was given control of the southern portion. In Europe, as had been agreed upon at a meeting of the Allies in Potsdam in the summer of 1945, Germany was divided into four occupation zones that would be controlled by Britain, France, the Soviet Union, and the United States, respectively. The city of Berlin was similarly split into four. Plans were made to prosecute war criminals in both Japan and Germany. In October 1945, the United Nations was created. People around the world celebrated the end of the conflict, but America’s use of atomic bombs and disagreements between the United States and the Soviet Union at Yalta and Potsdam would contribute to ongoing instability in the postwar world.
Section Summary
The way in which the United States fought the war in the Pacific was fueled by fear of Japanese imperialistic aggression, as well as anger over Japan’s attack on Pearl Harbor and its mistreatment of its enemies. It was also influenced by a long history of American racism towards Asians that dated back to the nineteenth century. From hostile anti-Japanese propaganda to the use of two atomic bombs on Japanese cities, America’s actions during the Pacific campaign were far more aggressive than they were in the European theater. Using the strategy of island hopping, the United States was able to get within striking distance of Japan. Only once they adopted this strategy were the Allied troops able to turn the tide against what had been a series of challenging Japanese victories. The war ended with Japan’s surrender.
The combined Allied forces had successfully waged a crusade against Nazi Germany, Italy, and Japan. The United States, forced to abandon a policy of nonintervention outside the Western Hemisphere, had been able to mobilize itself and produce the weapons and the warriors necessary to defeat its enemies. Following World War II, America would never again retreat from the global stage, and its early mastery of nuclear weapons would make it the dominant force in the postwar world.
Review Questions
Which of the following islands had to be captured in order to provide a staging area for U.S. bombing raids against Japan?
Sakhalin
Iwo Jima
Molokai
Reunion
B
What purpose did the Allied strategy of island hopping serve?
Allied forces intentionally avoided Japanese-held island strongholds that did not serve them strategically, instead securing locations that allowed them to interfere with Japanese communications and transportation routes. In this way, the Allies made their way towards Japan with limited military engagement. The goal was to get close enough to the Japanese home islands to achieve air superiority, paving the way for Allied assaults by air or water.
Why might President Truman have made the decision to drop the second atomic bomb on Nagasaki?
Truman wanted to end the war quickly and save lives by avoiding an invasion of the Japanese home islands. However, he might have achieved this by waiting for a definitive response from Japan following the bombing of Hiroshima. Truman may also have wanted to demonstrate America’s power to the Soviet Union and hoped that the unleashing of his nuclear arsenal would send a strong message to Stalin.
Critical Thinking Questions
Given that the Japanese war against China began in 1937 and German aggression began in Europe in 1936, why was it not until 1941 that the United States joined the war against the Axis powers? Was the decision to stay out of the war until 1941 a wise one on the part of the United States?
Should the United States have done more to help European Jews during the 1930s? What could it have done?
In what ways did World War II improve the status of women and African Americans in the United States?
Should the U.S. government have ordered the internment of Japanese Americans? Does the fear of espionage or sabotage justify depriving American citizens of their rights?
Did the United States make the right decision to drop atomic bombs on Japan?
Glossary
- Enola Gay
- the plane that dropped the atomic bomb on Hiroshima
- Manhattan Project
- the code name given to the research project that developed the atomic bomb


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aggregate
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a specific subgroup of a community or population
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benchmark
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a point of reference or standard against which measurements can be compared
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coalition
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a group of people and organizations who work to address community needs and solve community problems
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community engagement
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the process of working collaboratively with and through groups of people to identify the health needs of community residents and strategies to address those needs
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community health assessment (CHA)
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provides a comprehensive picture of a community’s current health status, factors that contribute to higher health risks or poorer health outcomes, and available community resources to improve health; purpose of CHA and subsequent community health improvement plan is to identify key health needs of a community and to address those needs through strategic intervention
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community health improvement plan (CHIP)
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a long-term systematic plan to address issues identified in the community health assessment that describes how the health department and the community will work together to improve population health
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community partners
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all persons, agencies, and organizations who have an investment in the community’s health and in the local public health system
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education
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the establishment and arrangement of events to facilitate learning and skill development
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gap analysis
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analysis that is performed to identify and address the disparity between what is desired and real-world conditions
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geographic information systems (GIS)
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software and technology that can store, visualize, analyze, and interpret spatial data
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health indicators
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numerical measures of health outcomes, such as morbidity and mortality, that have been analyzed and are used to compare rates or trends of priority community health outcomes and determinants of health
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learning
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the process of gaining knowledge and skills that lead to behavioral changes
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organizational health literacy
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the degree to which organizations equitably enable individuals to find, understand, and use information and services to inform health-related decisions and actions for themselves and others
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partnership
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relationship characterized by mutual cooperation and responsibilities among individuals and groups
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personal health literacy
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the degree to which individuals have the ability to find, understand, and use information and services to inform health-related decisions and actions for themselves and others
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primary data
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data collected by the assessor directly from community members; PHAB considers primary data to be data for which collection is conducted, contracted, or overseen by the health department
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qualitative data
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data expressed in word form that cannot be quantified; describe perspectives of individuals and populations
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quantitative data
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data expressed by amount in numerical terms
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secondary data
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data obtained through existing reports on the community that were collected by another entity or for a purpose other than community health assessment
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spatial data
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data that identify the geographic location of phenomena, provide an overview of the community in map form, and can be used to compare one part of the community to another
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vital statistics
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population data about births, deaths, marriages, and divorces in the United States


8.12: Web Retailing Laws
- List some critical laws that pertain to web retailing
Brick and mortar stores have been a primary source of sales for retailers for centuries. With technological advances in computers and the internet many retailers have turned to conducting business online in order to expand their sales. Online sales also provide the opportunity for consumers who might not otherwise have the means to physically go into a retail store to purchase products or who may live outside the retail stores physical location. Around the time of the new millennium the federal government began to recognize that there was a need for laws governing these types of transactions. The Uniform Commercial Code (UCC) has been the statutory law which governs the sale and/or lease of goods and contracts for the same. [1] The UCC decidedly began implementing laws which regulated online retail sales after it became apparent in the 1990s that e-commerce was here to stay.
E-contracts for the sale of goods are covered in Article 2 of the UCC’s guidelines. An agreement online is typically made by checking a box agreeing to the terms of a contract or acceptance of an offer. In July of 1999 a new act was created called the Uniform Computer Information Transaction Act (UCITA). This act is used as a guideline for licensure of computer information exclusively and is most pertinent if the retailer you are working for sells computer software. [2] Electronic signatures are also a means of conducting business transactions online. Electronic signatures were confirmed as a means of carrying out the sale or lease of goods and services online in 2000 under the Clinton administration when the Electronic Signatures in Global and National Commerce Act was approved by Congress. [3] Other laws retail managers should be familiar with when selling retail goods online have to do with international purchases. The United Nations has been beneficial with attempting to provide an outline for countries that are in agreement of their International Sale of Goods trade laws. [4]
Retail managers should become familiar with these laws as retail sales over the internet increase. While shopping in retail stores is still where the majority of sales are made for retailers shopping via the internet has grown significantly in recent years. “Researchers predicted a 15 percent growth in U.S. sales and total value for online shopping between 2016 and 2017, while offline only saw a 4.5 percent increase. There are almost as many people who prefer to shop in stores rather than online—with 51 percent of Americans preferring ecommerce, and 49 percent preferring heading into an actual store. However, a larger portion of millennials (67 percent) prefer shopping online over offline.” [5]
Contributors and Attributions
- Web Retailing Laws. Authored by : Freedom Learning Group. Provided by : Lumen Learning. License : CC BY: Attribution


16.8.0: Review Questions
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- Last updated
- Save as PDF
Review Questions
1 .
What step in the pain process involves the gate control theory of pain?
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transduction of pain
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transmission of pain
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perception of pain
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modification of pain
2 .
The nurse is providing a class to nursing students on chronic pain management. What example describes chronic pain?
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a patient admitted to the hospital for a femur fracture
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a patient experiencing back pain from a car accident last year
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a patient receiving first aid for burning their hand on the stove
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a patient experiencing a ruptured aneurysm
3 .
A patient is complaining of right ankle pain that feels “dull and aching.” The nurse documents this as what type of pain?
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cutaneous
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visceral
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somatic
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referred
4 .
The nurse is providing a class to nursing students about pain. How would the nurse define pain to the students?
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an unpleasant sensory and emotional experience associated with actual or potential tissue damage
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an objective experience that is defined by a pain rating scale
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an unpleasant sensation that can only be treated with medications
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an unpleasant sensation for a short duration and in a specific location
5 .
The nurse is caring for an older adult patient who has been experiencing back pain. The nurse asks the patient to rate their pain and the patient states “I am not in pain. I am fine.” The nurse knows the patient could have what factor impacting their perception of pain?
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medical diagnosis
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culture
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age
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cognitive function
6 .
The nurse is explaining the sympathetic response to pain to a student who has just started their orientation in the emergency department. What statement does the nurse make about the sympathetic response to pain?
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“It is an involuntary reaction to pain that keeps the body safe from danger.”
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“It helps the body relax and rest after perceived pain.”
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“It involves facial expressions and vocal expressions of pain.”
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“It can include emotions such as fear and anxiety in connection to pain.”
7 .
The nurse is caring for an infant patient and knows what physical response or sign is most likely going to be present in an infant in pain?
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increased blood pressure
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decreased heart rate
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crying
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withdrawal from touch
8 .
The nurse is caring for a patient experiencing chronic pain due to bladder cancer treatment. The nurse knows the patient is at risk for what type of behavioral response to pain?
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vocalization of pain
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social withdrawal
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algophobia
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catastrophizing
9 .
A patient dealing with chronic pain is seeking help with their anxiety. The patient states “My anxiety has gotten so much worse since this pain began.” The nurse can make what recommendation to the patient to treat anxiety in chronic pain?
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cognitive behavioral therapy
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opioid analgesics
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avoiding potential painful situations
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treating the chronic pain
10 .
The nurse is teaching a class on pain management and is discussing the physiologic response to pain. What would the nurse state is a sign of the sympathetic response to pain?
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lowering blood pressure
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directing the pancreas to create insulin
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slowing digestion
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constricting pupils to limit light
11 .
The nurse is caring for a patient who is struggling to cope with their chronic pain from cancer treatment. The nurse knows what factor can make a positive difference in the patient’s perception of pain?
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strong social support
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quitting their job
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avoidance
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catastrophizing
12 .
The nurse is caring for a preschool-aged patient who is admitted for abdominal pain. How would the nurse expect the patient to express their pain?
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catastrophizing
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accepting the pain is normal
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physical resistance and anger
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appear quiet and reserved
13 .
What is the definition of the placebo effect?
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when a patient thinks of the worst possible outcome for their pain
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when pain intervention proves to be effective because the patient believed it would be
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when the patient experiences extreme physical or mental suffering
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when the patient experiences pain because they expect it
14 .
The effect of trauma on the perception of pain is what type of factor?
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psychological
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psychosocial
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physiological
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cultural
15 .
The nurse is caring for an 80-year-old patient who has come into the emergency room to be monitored after a fall at home. The nurse knows the patient is at risk for what factor impacting their pain?
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age
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trauma
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distress
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expectation
16 .
A 40-year-old patient diagnosed with congestive heart failure is laughing and eating dinner with his visiting family. When asked to rate his pain on a numeric rating scale, the patient rates his pain as an 8 out of 10. What would the nurse conclude is the patient’s pain rating?
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It is what the patient says it is.
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It is less severe due to the patient’s behaviors.
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It is in anticipation of future pain.
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It is not accurate and the patient is exhibiting drug-seeking behaviors.
17 .
A patient comes to the emergency department with reports of decreased physical mobility, nausea, lack of appetite, and a “strange ache” in her back. What is the nurse’s initial focus?
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starting IV fluids for dehydration
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performing a comprehensive pain assessment
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ordering a physical therapy evaluation
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administering antiemetic medications
18 .
The nurse notices a 6-year-old patient grimacing and moaning as he walks to the bathroom. The patient does not respond when the nurse asks the patient to rate his pain on the numeric rating scale. What is the nurse’s response?
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Accept the patient’s lack of response as an indication of no pain.
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Clarify the patient’s pain rating using the FACES Pain Scale.
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Ask the patient’s parents to rate his pain.
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Ask the patient to rate his pain using the same scale again.
19 .
For a patient who is cognitively impaired and cannot use a pain scale, what vital sign changes may indicate the patient is experiencing pain?
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decreased blood pressure
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decreased respiratory rate
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increased heart rate
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increased oxygen saturation
20 .
What should the nurse document when evaluating an intervention for pain?
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current pain level and any symptoms
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vital signs
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head-to-toe assessment
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skin assessment
21 .
What is biofeedback therapy used for?
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controlling bodily functions such as heart rate to decrease pain
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controlling pain using a programmed pump
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decreasing pain through exercise and movement
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decreasing pain through positive imagery
22 .
The nurse is caring for a patient who was recently prescribed opioids following surgery. What is the best nursing intervention to prevent the side effect of constipation?
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increasing fluids and exercise
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monitoring for respiratory depression
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using stool softeners as needed
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increasing the patient’s diet to promote motility
23 .
The nurse is caring for a patient with pancreatitis that has been unable to take oral pain medications. What is the best action for the nurse?
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administering antiemetic medication
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using massage as a pain intervention
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initiating biofeedback therapy
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requesting a PCA order from the practitioner
24 .
The patient states they have been consuming acetaminophen frequently for the past several days to reduce their back pain. What side effect would the nurse be concerned about?
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gastrointestinal bleeding
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liver damage
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respiratory depression
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constipation
25 .
What safeguard should the nurse initiate to prevent medication errors when caring for a patient receiving a patient-controlled analgesic?
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checking the pump settings with the oncoming nurse
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decreasing the patient’s dose to prevent side effects
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monitoring the patient for respiratory depression
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ensuring the pump alarms are at full volume


7.2.25: Guess the Answer (Usable with Best Practices)
Query \(\PageIndex{1}\)
Overall Usability
Usable with Best Practices:
- The activity requires minimal adjustments by content authors.
Important Reminders
Use best practices for content authoring, including:
- Begin the activity with a correctly structured heading
- Add alt-text descriptions up to 150 characters for meaningful images
- Use good color contrast for meaningful visual information in images.
Visible Indication of Focus
The activity button has a visible indication of focus.
Color Contrast
The visible indication of focus has good contrast. The color contrast of meaningful visual elements and text with backgrounds must be ensured manually by the content author.
Keyboard Usability
The activity is usable with the keyboard.
No Keyboard Traps
There are no keyboard traps.
Magnification
The activity supports both magnification up to 200% and reflow of content with magnification up to 400% without a loss of content or functionality and without requiring horizontal scrolling.
Usability with Screen Reading Software
The activity is usable with screen reading software.