9.5: Use Properties of Angles, Triangles, and the Pythagorean Theorem (Part 2)
Use the Pythagorean Theorem
The Pythagorean Theorem is a special property of right triangles that has been used since ancient times. It is named after the Greek philosopher and mathematician Pythagoras who lived around 500 BCE.
Remember that a right triangle has a 90° angle, which we usually mark with a small square in the corner. The side of the triangle opposite the 90° angle is called the hypotenuse , and the other two sides are called the legs . See Figure \(\PageIndex{8}\).
Figure \(\PageIndex{8}\) - In a right triangle, the side opposite the 90° angle is called the hypotenuse and each of the other sides is called a leg.
The Pythagorean Theorem tells how the lengths of the three sides of a right triangle relate to each other. It states that in any right triangle, the sum of the squares of the two legs equals the square of the hypotenuse.
In any right triangle ΔABC,
\[a^{2} + b^{2} = c^{2}\]
where c is the length of the hypotenuse a and b are the lengths of the legs.
To solve problems that use the Pythagorean Theorem, we will need to find square roots. In Simplify and Use Square Roots we introduced the notation m and defined it in this way:
\[If\; m = n^{2}, then\; \sqrt{m} = n\; for\; n \geq 0\]
For example, we found that \(\sqrt{25}\) is 5 because 5 2 = 25.
We will use this definition of square roots to solve for the length of a side in a right triangle.
Use the Pythagorean Theorem to find the length of the hypotenuse.
Solution
| Step 1. Read the problem. | |
| Step 2. Identify what you are looking for. | the length of the hypotenuse of the triangle |
| Step 3. Name . Choose a variable to represent it. |
Let c = the length of the hypotenuse
|
| Step 4. Translate . Write the appropriate formula. Substitute. | $$\begin{split} a^{2} + b^{2} &= c^{2} \\ 3^{2} + 4^{2} &= c^{2} \end{split}$$ |
| Step 5. Solve the equation. | $$\begin{split} 9 + 16 &= c^{2} \\ 25 &= c^{2} \\ \sqrt{25} &= c^{2} \\ 5 &= c \end{split}$$ |
| Step 6. Check . | $$\begin{split} 3^{2} + 4^{2} &= \textcolor{red}{5}^{2} \\ 9 + 16 &\stackrel{?}{=} 25 \\ 25 &= 25\; \checkmark \end{split}$$ |
| Step 7. Answer the question. | The length of the hypotenuse is 5. |
Use the Pythagorean Theorem to find the length of the hypotenuse.
- Answer
-
c = 10
Use the Pythagorean Theorem to find the length of the hypotenuse.
- Answer
-
c = 17
Use the Pythagorean Theorem to find the length of the longer leg.
Solution
| Step 1. Read the problem. | |
| Step 2. Identify what you are looking for. | The length of the leg of the triangle |
| Step 3. Name . Choose a variable to represent it. |
Let b = the leg of the triangle Label side b
|
| Step 4. Translate . Write the appropriate formula. Substitute. | $$\begin{split} a^{2} + b^{2} &= c^{2} \\ 5^{2} + b^{2} &= 13^{2} \end{split}$$ |
| Step 5. Solve the equation. | $$\begin{split} 25 + b^{2} &= 169 \\ b^{2} &= 144 \\ b^{2} &= \sqrt{144} \\ b &= 12 \end{split}$$ |
| Step 6. Check . | $$\begin{split} 5^{2} + \textcolor{red}{12}^{2} &\stackrel{?}{=} 13^{2} \\ 25 + 144 &\stackrel{?}{=} 169 \\ 169 &= 169\; \checkmark \end{split}$$ |
| Step 7. Answer the question. | The length of the leg is 12. |
Use the Pythagorean Theorem to find the length of the leg.
- Answer
-
b = 8
Use the Pythagorean Theorem to find the length of the leg.
- Answer
-
b = 12
Kelvin is building a gazebo and wants to brace each corner by placing a 10-inch wooden bracket diagonally as shown. How far below the corner should he fasten the bracket if he wants the distances from the corner to each end of the bracket to be equal? Approximate to the nearest tenth of an inch.
Solution
| Step 1. Read the problem. | |
| Step 2. Identify what you are looking for. | the distance from the corner that the bracket should be attached |
| Step 3. Name . Choose a variable to represent it. |
Let x = the distance from the corner
|
| Step 4. Translate . Write the appropriate formula. Substitute. | $$\begin{split} a^{2} + b^{2} &= c^{2} \\ x^{2} + x^{2} &= 10^{2} \end{split}$$ |
| Step 5. Solve the equation. Isolate the variable. Use the definition of the square root. Simplify. Approximate to the nearest tenth. | $$\begin{split} 2x^{2} &= 100 \\ x^{2} &= 50 \\ x &= \sqrt{50} \\ b &\approx 7.1 \end{split}$$ |
| Step 6. Check . | $$\begin{split} a^{2} + b^{2} &= c^{2} \\ (\textcolor{red}{7.1})^{2} + (\textcolor{red}{7.1})^{2} &\stackrel{?}{\approx} 10^{2} \\ &Yes. \end{split}$$ |
| Step 7. Answer the question. | Kelvin should fasten each piece of wood approximately 7.1" from the corner. |
John puts the base of a 13-ft ladder 5 feet from the wall of his house. How far up the wall does the ladder reach?
- Answer
-
12 feet
Randy wants to attach a 17-ft string of lights to the top of the 15-ft mast of his sailboat. How far from the base of the mast should he attach the end of the light string?
- Answer
-
8 feet
Animation: The Sum of the Interior Angles of a Triangle
Similar Polygons
Example: Determine the Length of the Hypotenuse of a Right Triangle
Practice Makes Perfect
Use the Properties of Angles
In the following exercises, find (a) the supplement and (b) the complement of the given angle.
- 53°
- 16°
- 29°
- 72°
In the following exercises, use the properties of angles to solve.
- Find the supplement of a 135° angle.
- Find the complement of a 38° angle.
- Find the complement of a 27.5° angle.
- Find the supplement of a 109.5° angle.
- Two angles are supplementary. The larger angle is 56° more than the smaller angle. Find the measures of both angles.
- Two angles are supplementary. The smaller angle is 36° less than the larger angle. Find the measures of both angles.
- Two angles are complementary. The smaller angle is 34° less than the larger angle. Find the measures of both angles.
- Two angles are complementary. The larger angle is 52° more than the smaller angle. Find the measures of both angles.
Use the Properties of Triangles
In the following exercises, solve using properties of triangles.
- The measures of two angles of a triangle are 26° and 98°. Find the measure of the third angle.
- The measures of two angles of a triangle are 61° and 84°. Find the measure of the third angle.
- The measures of two angles of a triangle are 105° and 31°. Find the measure of the third angle.
- The measures of two angles of a triangle are 47° and 72°. Find the measure of the third angle.
- One angle of a right triangle measures 33°. What is the measure of the other angle?
- One angle of a right triangle measures 51°. What is the measure of the other angle?
- One angle of a right triangle measures 22.5°. What is the measure of the other angle?
- One angle of a right triangle measures 36.5°. What is the measure of the other angle?
- The two smaller angles of a right triangle have equal measures. Find the measures of all three angles.
- The measure of the smallest angle of a right triangle is 20° less than the measure of the other small angle. Find the measures of all three angles.
- The angles in a triangle are such that the measure of one angle is twice the measure of the smallest angle, while the measure of the third angle is three times the measure of the smallest angle. Find the measures of all three angles.
- The angles in a triangle are such that the measure of one angle is 20° more than the measure of the smallest angle, while the measure of the third angle is three times the measure of the smallest angle. Find the measures of all three angles.
Find the Length of the Missing Side
In the following exercises, Δ ABC is similar to Δ XYZ. Find the length of the indicated side.
- side b
- side x
On a map, San Francisco, Las Vegas, and Los Angeles form a triangle whose sides are shown in the figure below. The actual distance from Los Angeles to Las Vegas is 270 miles.
- Find the distance from Los Angeles to San Francisco.
- Find the distance from San Francisco to Las Vegas.
Use the Pythagorean Theorem
In the following exercises, use the Pythagorean Theorem to find the length of the hypotenuse.
Find the Length of the Missing Side
In the following exercises, use the Pythagorean Theorem to find the length of the missing side. Round to the nearest tenth, if necessary.
In the following exercises, solve. Approximate to the nearest tenth, if necessary.
- A 13-foot string of lights will be attached to the top of a 12-foot pole for a holiday display. How far from the base of the pole should the end of the string of lights be anchored?
- Pam wants to put a banner across her garage door to congratulate her son on his college graduation. The garage door is 12 feet high and 16 feet wide. How long should the banner be to fit the garage door?
- Chi is planning to put a path of paving stones through her flower garden. The flower garden is a square with sides of 10 feet. What will the length of the path be?
- Brian borrowed a 20-foot extension ladder to paint his house. If he sets the base of the ladder 6 feet from the house, how far up will the top of the ladder reach?
Everyday Math
- Building a scale model Joe wants to build a doll house for his daughter. He wants the doll house to look just like his house. His house is 30 feet wide and 35 feet tall at the highest point of the roof. If the dollhouse will be 2.5 feet wide, how tall will its highest point be?
- Measurement A city engineer plans to build a footbridge across a lake from point X to point Y, as shown in the picture below. To find the length of the footbridge, she draws a right triangle XYZ, with right angle at X. She measures the distance from X to Z, 800 feet, and from Y to Z, 1,000 feet. How long will the bridge be?
Writing Exercises
- Write three of the properties of triangles from this section and then explain each in your own words.
- Explain how the figure below illustrates the Pythagorean Theorem for a triangle with legs of length 3 and 4.
Self Check
(a) After completing the exercises, use this checklist to evaluate your mastery of the objectives of this section.
(b) What does this checklist tell you about your mastery of this section? What steps will you take to improve?
Contributors and Attributions
-
Lynn Marecek (Santa Ana College) and MaryAnne Anthony-Smith (Formerly of Santa Ana College). This content is licensed under Creative Commons Attribution License v4.0 "Download for free at<EMAIL_ADDRESS>."


 The parts of the mouth include the teeth, the gums, the tongue, the oral vestibule (the space between the gums, lips, and teeth), and the oral cavity proper (the space behind the teeth and gums).
Multiple Choice
Which of the following is NOT a way the normal microbiota of the intestine helps to prevent infection?
- It produces acids that lower the pH of the stomach.
- It speeds up the process by which microbes are flushed from the digestive tract.
- It consumes food and occupies space, outcompeting potential pathogens.
- It generates large quantities of oxygen that kill anaerobic pathogens.
- Answer
-
D
What types of microbes live in the intestines?
- Diverse species of bacteria, archaea, and fungi, especially Bacteroides and Firmicutes bacteria
- A narrow range of bacteria, especially Firmicutes
- A narrow range of bacteria and fungi, especially Bacteroides
- Archaea and fungi only
- Answer
-
A
Fill in the Blank
The part of the gastrointestinal tract with the largest natural microbiota is the _________.
- Answer
-
Large intestine or colon
Short Answer
How does the diarrhea caused by dysentery differ from other types of diarrhea?
24.2: Microbial Diseases of the Mouth and Oral Cavity
Despite the presence of saliva and the mechanical forces of chewing and eating, some microbes thrive in the mouth. These microbes can cause damage to the teeth and can cause infections that have the potential to spread beyond the mouth and sometimes throughout the body.
Multiple Choice
What pathogen is the most important contributor to biofilms in plaque?
- Staphylococcus aureus
- Streptococcus mutans
- Escherichia coli
- Clostridium difficile
- Answer
-
B
What type of organism causes thrush?
- a bacterium
- a virus
- a fungus
- a protozoan
- Answer
-
C
In mumps, what glands swell to produce the disease’s characteristic appearance?
- the sublingual glands
- the gastric glands
- the parotid glands
- the submandibular glands
- Answer
-
C
Which of the following is true of HSV-1?
- It causes oral thrush in immunocompromised patients.
- Infection is generally self-limiting.
- It is a bacterium.
- It is usually treated with amoxicillin.
- Answer
-
B
Fill in the Blank
When plaque becomes heavy and hardened, it is called dental calculus or _________.
- Answer
-
tartar
Short Answer
Why do sugary foods promote dental caries?
24.3: Bacterial Infections of the Gastrointestinal Tract
Major causes of gastrointestinal illness include Salmonella spp., Staphylococcus spp., Helicobacter pylori , Clostridium perfringens , Clostridium difficile , Bacillus cereus , and Yersinia bacteria. C. difficile is an important cause of hospital acquired infection. Vibrio cholerae causes cholera, which can be a severe diarrheal illness. Different strains of E. coli , including ETEC, EPEC, EIEC, and EHEC, cause different illnesses with varying degrees of severity.
Multiple Choice
Which type of E. coli infection can be severe with life-threatening consequences such as hemolytic uremic syndrome?
- ETEC
- EPEC
- EHEC
- EIEC
- Answer
-
C
Which species of Shigella has a type that produces Shiga toxin?
- S. boydii
- S. flexneri
- S. dysenteriae
- S. sonnei
- Answer
-
C
Which type of bacterium produces an A-B toxin?
- Salmonella
- Vibrio cholera
- ETEC
- Shigella dysenteriae
- Answer
-
B
Fill in the Blank
Antibiotic associated pseudomembranous colitis is caused by _________.
- Answer
-
Clostridium difficile
Critical Thinking
Why does use of antibiotics and/or proton pump inhibitors contribute to the development of C. difficile infections?
Why did scientists initially think it was unlikely that a bacterium caused peptic ulcers?
Does it makes a difference in treatment to know if a particular illness is caused by a bacterium (an infection) or a toxin (an intoxication)?
24.4: Viral Infections of the Gastrointestinal Tract
Common viral causes of gastroenteritis include rotaviruses, noroviruses, and astroviruses. Hepatitis may be caused by several unrelated viruses: hepatitis viruses A, B, C, D, and E. The hepatitis viruses differ in their modes of transmission, treatment, and potential for chronic infection.
Multiple Choice
Which form of hepatitisvirus can only infect an individual who is already infected with another hepatitisvirus?
- HDV
- HAV
- HBV
- HEV
- Answer
-
A
Which cause of viral gastroenteritis commonly causes projectile vomiting?
- hepatitisvirus
- Astroviruses
- Rotavirus
- Noroviruses
- Answer
-
D
Fill in the Blank
Jaundice results from a buildup of _________.
- Answer
-
bilirubin
Short Answer
Which forms of viral hepatitis are transmitted through the fecal-oral route?
Critical Thinking
Based on what you know about HBV, what are some ways that its transmission could be reduced in a health-care setting?
24.5: Protozoan Infections of the Gastrointestinal Tract
Like other microbes, protozoa are abundant in natural microbiota but can also be associated with significant illness. Gastrointestinal diseases caused by protozoa are generally associated with exposure to contaminated food and water, meaning that those without access to good sanitation are at greatest risk. Even in developed countries, infections can occur and these microbes have sometimes caused significant outbreaks from contamination of public water supplies.
Multiple Choice
Which protozoan is associated with the ability to cause severe dysentery?
- Giardia lamblia
- Cryptosporidium hominis
- Cyclospora cayetanesis
- Entamoeba histolytica
- Answer
-
D
Which protozoan has a unique appearance, with a blue halo, when viewed using ultraviolet fluorescence microscopy?
- Giardia lamblia
- Cryptosporidium hominis
- Cyclospora cayetanesis
- Entamoeba histolytica
- Answer
-
C
The micrograph shows protozoans attached to the intestinal wall of a gerbil. Based on what you know about protozoan intestinal parasites, what is it?
(credit: Dr. Stan Erlandsen, Centers for Disease Control and Prevention)
- Giardia lamblia
- Cryptosporidium hominis
- Cyclospora cayetanesis
- Entamoeba histolytica
Fill in the Blank
Chronic _________ infections cause the unique sign of disease of greasy stool and are often resistant to treatment.
- Answer
-
giardia
Short Answer
What is an O&P exam?
24.6: Helminthic Infections of the Gastrointestinal Tract
Helminths are widespread intestinal parasites. These parasites can be divided into three common groups: round-bodied worms also described as nematodes, flat-bodied worms that are segmented (also described as cestodes), and flat-bodied worms that are non-segmented (also described as trematodes). The nematodes include roundworms, pinworms, hookworms, and whipworms. Many of these parasites are so well adapted to the human host that there is little obvious disease.
Multiple Choice
What is another name for Trichuris trichiura ?
- pinworm
- whipworm
- hookworm
- ascariasis
- Answer
-
B
Which type of helminth infection can be diagnosed using tape?
- pinworm
- whipworm
- hookworm
- tapeworm
- Answer
-
A
Fill in the Blank
Liver flukes are often found in the _________ duct.
- Answer
-
bile
Short Answer
Why does the coughing up of worms play an important part in the life cycle of some helminths, such as the roundworm Ascaris lumbricoides ?
Critical Thinking
Cases of strongyloidiasis are often more severe in patients who are using corticosteroids to treat another disorder. Explain why this might occur.


6.3: Nutrition and Chronic Neurological Illnesses
By the end of this section, you should be able to:
- 6.2.1 Discuss the impact of nutrition on neurological illness.
- 6.2.2 Discuss the impact of nutrition on psychiatric illness.
Nutritional Requirement for Optimal Neurological Health
Although the development of neurologic conditions varies in process, there are several common threads in reduced cognition and other neurologic functions. Neurologic chronic conditions are associated with a variety of factors, such as increased oxidative stress , neuroinflammation , and a disruption in energy metabolism . Each of these factors can be influenced and modified by dietary intake.
The nurse should screen all clients with neurologic illness for malnutrition in conjunction with the health care team, using the tools described in Applying Clinical Judgment to Promote Nutrition for Neurological Wellness. This screening is especially important because clients with neurological conditions may have difficulty chewing or swallowing . Aphasia , apraxia , depression , or altered cognitive states may further challenge adequate intake. Key nutritional recommendations for preventing neurologic deterioration in neurodegenerative conditions are provided in this section.
The effect of specific diets (such as ketogenic and Mediterranean diet) among clients with neurologic conditions, such as epilepsy, traumatic and atraumatic brain injury, multiple sclerosis, autism, and various neurodegenerative conditions, such as Alzheimer’s disease, Parkinson’s disease, and amyotrophic lateral sclerosis (ALS), have been explored in various clinical trials and are described in this section. While the type of diet is important, it is fundamental that the nurse assess the client’s physical ability to eat. The nurse should assess the client’s current food intake, signs of fatigue, loss of movement, and evidence of dry mouth as these findings can make eating challenging. Meeting the nutritional requirements of clients who have difficulty swallowing ( dysphagia ) secondary to a stroke or other condition can be particularly challenging because these clients require additional diet modifications so that foods can be consumed safely to decrease the risk for choking or aspiration.
Meeting the nutritional requirements of clients with a stroke can be challenging, given the potential for difficulty swallowing (dysphagia). Although the ideal diet for a client who has had a stroke is generally similar to a cardiac diet (low salt, low fat, high fiber), this may be challenging.
Ketogenic Diet
The ketogenic diet is high in fat and low in carbohydrates, and has been used to facilitate treatment for clients with drug-resistant epilepsy . The impact of the ketogenic diet, as well as variations like a modified Atkins diet or low glycemic diets is to promote the formation of ketone bodies. The brain uses ketones to generate energy, and this type of diet reduces the magnitude of glycolysis . Although the science is still somewhat unclear, it is thought that this generation of ketone bodies alters the metabolism of certain neurotransmitters and improves mitochondrial function in a fashion that reduces oxidative stress , improves mitochondrial function , and activates certain signaling pathways (Francis & Stevenson; Miller, et al., 2020).
The beneficial impact of ketogenic diets in clients with epilepsy is well known to be a reduction in seizures that have been previously intractable to drug therapy. In addition, the impact of a ketogenic diet in children with epilepsy often includes an improvement in cognitive function and a reduced rate of developmental delays, if initiated very early. However, the impact on cognition may be directly related to the diet or to a brain injury associated with uncontrolled seizures.
The ketogenic diet shows some promise in other conditions as well, such as multiple sclerosis , autism , and Alzheimer’s disease (Li, 2021). In a study of clients with multiple sclerosis, a ketogenic diet may improve concentration, attention, and memory (Francis & Stevenson, 2018). Although limited data exists due to small sample sizes and difficulty with blinding procedures, a ketogenic diet has been shown to improve autistic behavior, but individual food preferences and the gastrointestinal impact of this diet may impact feasibility (Francis & Stevenson, 2018). The effect of the ketogenic diet is to produce a state of ketosis, and among individuals with Alzheimer’s disease, a modest improvement of cognitive function occurs when ketosis is achieved. However, among individuals with Alzheimer’s disease, cognitive improvement was observed only when clients engaged in a ketogenic diet achieved ketosis, even among those with severe Alzheimer’s disease (Tabaie, et al., 2022).
Mediterranean Diet
While the Mediterranean diet (Figure 6.4) has shown effectiveness in preventing heart disease, the antioxidant and anti-inflammatory benefit of this diet can help prevent stroke events and slow cognitive decline in clients with Alzheimer’s disease, in part because of the long-chain polyunsaturated fatty acids and olive oil. Moreover, the polyphenols obtained from fresh fruits and vegetables have been shown to mitigate the phosphorylation of tau protein , preventing tangle formation, and to negate beta-amyloid aggregation in the brain. The net effect of reducing oxidative stress and neuroinflammation is to enhance neurogenesis , improve transmission across synapses, and reduce neuronal death (Román et al., 2019).
Alternative Food and Supplement Options
While the ketogenic and Mediterranean diets have shown promise in the prevention and management of neurologic conditions, the metabolism of lipids in the brain are dramatically disrupted when there is an excessive intake of carbohydrates , particularly those found in processed foods such as high-fructose corn syrup and artificial sweeteners. However, complex carbohydrates, such as those found in fresh fruit, vegetables, and high-fiber cereal grains, are recommended for the management of cognitive decline (Román et al., 2019).
Client Teaching
In general, a diet rich in fruits and vegetables, whole grains, nuts, seeds, fish, meats, eggs, dairy products, healthy fats (olive oil, avocado, coconut, and flaxseed oils), and probiotic-rich foods (yogurt, kimchi, kefir, sauerkraut), as well as fresh herbs and spices are neuroprotective.
For clients with neurologic conditions, preventing further brain inflammation can mitigate or slow degenerative processes. Resveratrol is a polyphenolic compound that is present in grapes, mulberries, tea, seeds, some cereals, and red wine consumed in moderation. It can protect the body from developing increased levels of triglycerides and cholesterol and can have a positive effect in the early stages of neurodegenerative disorders (Oppedisano et al., 2020).
Ensuring optimal intake or supplementation of vitamins and certain minerals, such as magnesium, can prevent acute episodes of brain fog and fatigue in persons with MS . When supplementing clients with deficiency of vitamins A, B 12 , and D 3 , it is helpful to administer these supplements with magnesium , as they do not compete with one another during for absorption. Reducing carbohydrate intake can also help to mitigate the fatigue of MS. Coenzyme Q10 ( CoQ10 ) has been shown to have a significant antioxidant effect to produce energy and is well known for the prevention of heart disease, but it also has neuroprotective effects. CoQ10 is not available in foods but is synthesized by the body. In clients who have experienced ataxia because of neurologic conditions, supplementation of CoQ10 has been shown to improve both gait and posture (Oppedisano et al., 2020).
A diet high in antioxidants and fiber can help fight inflammation in clients with MS and will slow further demyelination and prevent constipation. Some sources suggest that a ketogenic diet prevents or slows symptom to manifest in clients with MS (Dynka et al., 2022).
Read the following clinical scenario and then answer the questions that follow. This case study is a follow-up to Case Study Part A.
During John’s visit it becomes apparent that he is experiencing some cognitive decline. The health care provider is recommending further neurological evaluation for possible dementia. The provider is also concerned about the client’s weight loss and wants the nurse to work with John to improve his food intake.
-
Increase intake of complex carbohydrates.
-
Switch to drinking diet beverages with artificial sweeteners.
-
Limit fluid intake and focus on solid food intake.
-
Vitamins and supplements are used as a last resort.
-
Vitamins and supplements do not contain adequate amounts of needed nutrients.
-
Taking vitamins and supplements may be confusing for the client and difficult to remember to take.
-
Research shows that eating a nutrient-rich diet is the best source of micronutrients to support cognition.


7.1: Introduction
Module 7
Weathering, Erosion, and Sedimentary Rocks
Introduction
This module includes two chapters that are very closely related. Weathering, the subject of Chapter 5, is the process that breaks down existing Earth materials and leads to the creation of soil. Most materials can be broken down by weathering, but some materials are more susceptible than others. For example, igneous rocks are fairly resistant to weathering, but over long periods of time they still erode away. In addition, there are a number of different processes that cause weathering, including mechanical and chemical processes. Different processes affect different materials at different rates, which leads to the formation of different types of sedimentary rocks, as you will discover as you read through Chapter 6.
We are particularly interested in the history and events that occur on the surface of the Earth both because it is easier to directly observe and test, and it has direct relevance to our lives and our own history. Sedimentary rocks are the pages in which Earth’s history is written, since they contain powerful environmental indicators, traces of life, and chemical signatures that can inform us about a wealth of subjects from the occurrence of ancient catastrophes to the productivity of life.
The identification of sedimentary rocks is more than applying names, since each name is a loaded term that conveys information regarding its history, where it was formed, potentially when it was formed, and the processes that lead to its formation. Each sedimentary rock is a puzzle and by identifying a set of rocks, how they are layered, the fossils within, and patterns in the rocks a geologist can reconstruct an entire environment and ecosystem. Solving these puzzles is both an academic exercise to better understand the world around us as well as a tool for finding the resources that are important to our lives. In particular, fossil fuels as well as many other natural resources are made of, or are contained within, sedimentary rocks such as coal, natural gas, petroleum, salt, and cement, and more. Therefore, a better understanding of sedimentary rocks and how and where they are formed directly influences your everyday life.
Select an image to view larger
Module Objectives
At the completion of this module you will be able to:
- Explain why rocks formed at depth in the crust are susceptible to weathering at the surface.
- Describe the main processes of mechanical weathering and its products.
- Describe the main processes of chemical weathering and its products.
- Explain the type of weathering processes that are likely to have taken place to produce a particular sediment deposit.
- Discuss the relationships between weathering and soil formation, the origins of soil horizons, and some of the different types of soil.
- Explain the geological carbon cycle, and how variations in rates of weathering can lead to climate change.
- Describe the differences between cobbles, pebbles, sand, silt, and clay and explain how clast size relates to the mode of transport.
- Describe the various types of clastic and chemical sedimentary rocks, and apply your understanding of their characteristics to infer past depositional environments and climates.
- Differentiate between terrestrial and marine depositional environments, and explain how the formation of sedimentary basins can be related to plate tectonic processes.
- Explain the importance of and differences between groups, formations, and members
Activities Overview
See the Schedule of Work for dates of availability and due dates.
Be sure to read through the directions for all of this module’s activities before getting started so that you can plan your time accordingly. You are expected to work on this course throughout the week.
Read
Physical Geology by Steven Earle
- Chapter 5 (Weathering)
- Chapter 6 (Sediments and Sedimentary Rocks)
Module 7 Assignment: Sedimentary Rock Lab
10 points
After you complete the reading, you can start working on Module 7 Assignment – Sedimentary Rock Lab.
Module 7 Quiz
10 points
Module 7 Quiz has 10 multiple-choice questions and is based on the content of the Module 7 readings and Assignment 7.
The quiz is worth a total of 10 points (1 points per question). You will have only 10 minutes to complete the quiz, and you may take this quiz only once. Note : that is not enough time to look up the answers!
Make sure that you fully understand all of the concepts presented and study for this quiz as though it were going to be proctored in a classroom, or you will likely find yourself running out of time.
Keep track of the time, and be sure to look over your full quiz results after you have submitted it for a grade.
Your Questions and Concerns…
Please contact me if you have any questions or concerns.
General course questions : If your question is of a general nature such that other students would benefit from the answer, then go to the discussions area and post it as a question thread in the “General course questions” discussion area.
Personal questions : If your question is personal, (e.g. regarding my comments to you specifically), then send me an email from within this course.


7.3: References
Beasley, R., Chien, J., Douglas, J., Eastlake, L., Farah, C., King, G., Moore, R., Pilcher, J., Richards, M., Smith, S., & Walters, H. (2016). Target oxygen saturation range: 92–96% versus 94–98%. Respirology , 22(1), 200–202
Fech, T., Penrod, J., Battistone, M., Sawitzke, A., & Stults, B. (2012). The prevalence and clinical correlates of an auscultatory gap in systemic sclerosis patients. International Journal of Rheumatology , doi: 10.1155/2012/590845
Jarvis (2014). Physical Examination & Health Assessment (2nd Canadian edition). Elsevier Canada: Toronto
Leduc, D., & Woods, S., (2017). Canadian Paediatric Society Position Statement: Temperature measurement in paediatrics. Retrieved from: www.cps.ca/en/documents/posit...re-measurement
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Mazerolle, S., Ganio, M., Casa, D., Vingren, J., & Klau, J. (2011). Is oral temperature an accurate measurement of deep body temperature? A systematic review. Journal of Athletic Training , 46(5), 566–573.
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3.9: Benzyne
After completing this section, you should be able to
- identify the reagents and conditions required to produce phenol from chlorobenzene on an industrial scale.
- write the mechanism for the conversion of an alkyl halide to a phenol through a benzyne intermediate.
- discuss the experimental evidence which supports the existence of benzyne intermediates.
- discuss the bonding in benzyne, and hence account for its high reactivity.
Halobenzenes without electron-withdrawing substituents don’t react with nucleophiles under most conditions. At high temperature and pressure, however, even chlorobenzene can be forced to react. The elimination-addition mechanism of nucleophilic aromatic substitution involves the remarkable intermediate called benzyne or arynes.
Chemists at the Dow Chemical Company discovered in 1928 that phenol could be prepared on an industrial scale by treatment of chlorobenzene with dilute aqueous NaOH at 340°C under 170 atm pressure.
A similar substitution reaction occurs with other strong bases. Treatment of bromobenzene with potassium amide (KNH 2 ) in liquid NH 3 solvent (-33°C), for instance, gives aniline. Curiously, though, when using bromobenzene labeled with radioactive 14 C at the C1 position, the substitution product has equal amounts of the label at both C1 and C2, implying the presence of a symmetrical reaction intermediate in which C1 and C2 are equivalent.
Elimination-Addition Mechanism of Nucleophilic Aromatic Substitution. Arynes
The mechanism of this type of reaction has been studied extensively, and much evidence has accumulated in support of a stepwise process, which proceeds first by base-catalyzed elimination of hydrogen halide \(\left( \ce{HX} \right)\) from the aryl halide - as illustrated below for the amination of bromobenzene:
Step 1: Elimination
The product of the elimination reaction is a highly reactive intermediate \(9\) called benzyne , or dehydrobenzene , which differs from benzene in having two less hydrogen and an extra bond between two ortho carbons. Benzyne reacts rapidly with any available nucleophile, in this case the solvent, ammonia, to give an addition product:
Step 2: Addition
The electronic structure of benzyne, shown in Figure \(\PageIndex{1}\), is that of a highly distorted alkyne. Although a typical alkyne triple bond uses sp -hybridized carbon atoms, the benzyne triple bond uses sp 2 -hybridized carbons. Furthermore, a typical alkyne triple bond has two mutually perpendicular \(\pi\) bonds formed by p – p overlap, but the benzyne triple bond has one \(\pi\) bond formed by p – p overlap and one \(\pi\) bond formed by sp 2 – sp 2 overlap. The latter \(\pi\) bond is in the plane of the ring and is very weak.
Disubstituted Substrates
The rearrangements in these reactions result from the attack of the nucleophile at one or the other of the carbons of the extra bond in the intermediate. With benzyne the symmetry is such that no rearrangement would be detected. With substituted benzynes isomeric products may result. That is, the entering group does not always occupy the same position on the ring as that vacated by the halogen substituent . For example, the hydrolysis of 4-chloromethylbenzene at \(340^\text{o}\) gives an equimolar mixture of 3- and 4-methylbenzenols:
Thus 4-methylbenzyne, \(10\), from the reaction of hydroxide ion with 4-chloro-1-methylbenzene gives both 3- and 4-methylbenzenols:
Even more striking is the exclusive formation of 3-methoxybenzenamine in the amination of 2-chloromethoxybenzene. Notice that this result is a violation of the principle of least structural change:
When p -chlorotoluene is reacted with NaOH, two products are seen. While when m -chlorotoluene is reacted with NaOH, three products are seen. Explain this.
- Answer
-
You need to look at the benzyne intermediates. The para substituted only allows for two products, while the para produces two different alkynes which give three different products.
Make certain that you can define, and use in context, the key terms below.
- benzyne
- elimination-addition mechanism
An elimination-addition mechanism involves the elimination of the elements of a small molecule from a substrate to produce a highly reactive intermediate, which then undergoes an addition reaction.


9.13: Prelude to the Afternoon of a Faun
Though the piece was composed in the late 19th century, Prelude to the Afternoon of a Faun is seen by no less a figure of modernism as Pierre Boulez as the beginning of modern music. If you’re interested, here is an English translation of the Mallarme poem upon which Debussy based his composition.
Introduction
Prélude à l’après-midi d’un faune ( L. 86 ), known in English as Prelude to the Afternoon of a Faun , is a symphonic poem for orchestra by Claude Debussy, approximately 10 minutes in duration. It was first performed in Paris on December 22, 1894, conducted by Gustave Doret.
Background
The composition was inspired by the poem L’après-midi d’un faune by Stéphane Mallarmé. Debussy’s work later provided the basis for the ballet Afternoon of a Faun , choreographed by Vaslav Nijinsky. It is one of Debussy’s most famous works and is considered a turning point in the history of music; Pierre Boulez has said he considers the score to be the beginning of modern music, observing that “the flute of the faun brought new breath to the art of music.” It is a work that barely grasps onto tonality and harmonic function.
About his composition Debussy wrote:
The music of this prelude is a very free illustration of Mallarmé’s beautiful poem. By no means does it claim to be a synthesis of it. Rather there is a succession of scenes through which pass the desires and dreams of the faun in the heat of the afternoon. Then, tired of pursuing the timorous flight of nymphs and naiads, he succumbs to intoxicating sleep, in which he can finally realize his dreams of possession in universal Nature.
Paul Valéry reported that Mallarmé himself was unhappy with his poem being used as the basis for music: “He believed that his own music was sufficient, and that even with the best intentions in the world, it was a veritable crime as far as poetry was concerned to juxtapose poetry and music, even if it were the finest music there is.”
However, Maurice Dumesnil states in his biography of Debussy that Mallarmé was enchanted by Debussy’s composition, citing a short letter from Mallarmé to Debussy that read: “I have just come out of the concert, deeply moved. The marvel! Your illustration of the Afternoon of a Faun, which presents a dissonance with my text only by going much further, really, into nostalgia and into light, with finesse, with sensuality, with richness. I press your hand admiringly, Debussy. Yours, Mallarmé.”
The opening flute solo is one of the most famous passages in the orchestral repertoire, consisting of a chromatic descent to a tritone below the original pitch, and the subsequent ascent.
Composition
The work is scored for three flutes, two oboes, cor anglais, two clarinets in A and Bb, two bassoons, four horns, two harps, two crotales and strings.
Although it is tempting to call this piece a tone poem, there is very little musical literalism in the piece; instead, the slow and mediated melody and layered orchestration as a whole evoke the eroticism of Mallarmé’s poem.
[This prelude] was [Debussy’s] musical response to the poem of Stephane Mallarmé (1842–1898), in which a faun playing his pan-pipes alone in the woods becomes aroused by passing nymphs and naiads, pursues them unsuccessfully, then wearily abandons himself to a sleep filled with visions. Though called a “prelude,” the work is nevertheless complete – an evocation of the feelings of the poem as a whole.
The Prélude at first listening seems improvisational and almost free-form; however, closer observation will demonstrate that the piece consists of a complex organization of musical cells, motifs carefully developed and traded between members of the orchestra. A close analysis of the piece reveals a high amount of consciousness of composition on Debussy’s part.
The main musical themes are introduced by woodwinds, with delicate but harmonically advanced underpinnings of muted horns, strings and harp. Recurring tools in Debussy’s compositional arsenal make appearances in this piece: extended whole-tone scale runs, harmonic fluidity without lengthymodulations between central keys, and tritones in both melody and harmony. The development of the slow main theme transitions smoothly between 9/8, 6/8, and 12/8 meters. Debussy enacts voicings and shading in his orchestration to a high degree, allowing the main melodic cell to move from solo flute tooboe, back to solo flute, then two unison flutes (yielding a completely different atmosphere to the melody), then clarinet, etc. Even the accompanimentexplores alternate voicings; the flute duo’s crescendo during their melodic cells accompany legato strings with violas carrying the soprano part over alto violins (the tone of a viola in its upper register being especially pronounced).
Contributors and Attributions
- Authored by : Elliott Jones. Provided by : Santa Ana College. Located at : http://www.sac.edu . License : CC BY: Attribution
- Prelude to the Afternoon of a Faun. Provided by : Wikipedia. Located at : http://en.Wikipedia.org/wiki/Pr%C3%A9lude_%C3%A0_l%27apr%C3%A8s-midi_d%27un_faune . License : CC BY-SA: Attribution-ShareAlike


2.2: Person- and Family-Centered Care
By the end of this section, you will be able to:
- Describe nursing interventions to care for all persons assigned female at birth and their families during family-centered care
- Identify challenges to delivering the best care for all families and persons assigned female at birth across a range of cultures, religious backgrounds, and family structures
- Discuss barriers to care for LGBTQIA+, disabled, and culturally diverse persons and families that the nurse can help mitigate
In 1970, the sociologists Firth and Firth (2014) defined family and kinship as “a set of ties socially recognized to exist between persons because of their genealogical connection … relationships thought to be created between them by marriage and/or procreation of children” (p. 1). In 2023, family continues to be seen as a group of people related by kinship; however, kinship is now made of many different types of connections, such as adoption, surrogacy, friendship, cohabitation, and fostering. Other types of families are single-parent, dual-career, single adult, extended, and blended or binuclear families. The nurse cares for a person while considering their family’s role or influence on the person.
Communities and cultures include, but are not limited to, LGBTQIA+ persons, persons speaking other languages, religious communities, and persons with disabilities ; these differences in social and ethnic backgrounds, gender, and sexual orientation represent a community’s diversity (Servaes et al., 2022). The nurse uses inclusive language and advocates for policies that allow all persons to feel included in the health-care process. The nurse should also find individual ways to care for those with disabilities to respect their autonomy yet provide needed assistance.
Care of Families
Nurses encounter people from a variety of backgrounds; therefore, it is essential that nurses provide culturally competent care. The lifelong process of applying evidence-based nursing in agreement with the cultural values, beliefs, worldview, and practices of patients to produce improved patient outcomes is called cultural competence . The process of determining proper care and providing the best treatment for a person by understanding, respecting, and integrating a person’s cultural beliefs into their health care is called culturally responsive care . When people are valued for all aspects of their identity, background, and experiences, they feel safe, understood, and, most importantly, valued. Culturally responsive care is required for a trusting, effective nurse-patient relationship. Nurses must be intentional in learning about other cultures and belief systems.
Influence of Family Structure
Family structure includes the people considered family members, where the person falls in the birth/sibling order, how many parents are in the household, whether a parent is single by choice or by circumstances, nuclear or extended families, and the origin of the family. Family structure helps people determine their roles in society. Dysfunctional families lead to persons with mental health issues, trauma or abuse, abandonment, and neglect. Functional families lead to accomplishing tasks that lead to individual well-being, the ability to adapt to changes, and the ability to balance individual needs with family needs (Booysen et al., 2021).
Stepparents’ Rights and Responsibilities
In the United States, stepparents have limited legal rights and responsibilities. The legal authority for decision making belongs to the two biological parents. The stepparent can help their spouse, the biological parent of the child, but cannot make decisions regarding school, medical care, religion, or other important matters related to the child. If the stepparent and the biological parent divorce, some states will allow visitation rights to the stepparent.
Paperwork allowing the stepparent to seek care for patients may exist, for example, a signed consent-to-treat letter that is notarized and signed by both biological parents or legal guardian(s).
A stepparent can adopt the child if the other biological person agrees to terminate their parental rights. The courts state that a stepparent must be married to the biological parent for a year and live with the child for at least 6 months to be eligible to adopt the child (Law Offices of Hector A. Montoya, 2021).
Dual-Career Family
A dual-career family is defined as a household in which both parents work. In a survey of families from 2015 to 2017 (U.S. Bureau of Labor Statistics, 2020), dual-career families with children under 6 years of age brought in an income $53,873 higher than single-career families (not single-family households). In dual-career families, health insurance is usually available and affordable compared to households without employment. The issues or concerns of these families are related to time management, such as not having enough time to deal with family responsibilities. The increased stress of meeting all family members' needs plus career needs may create role conflict both professionally and in relation to the family. Women may experience more stress than men in a dual-career couple due to women still taking on most household tasks and childcare (Center for Equity, Gender, & Leadership [EGAL], 2020). When interviewing families, the nurse should focus on gathering information on how the family roles are assumed by each partner.
Single-Career Family
A single-career family is defined as a household in which one parent works and the other stays home. In the past, this pattern meant that the stay-at-home parent was the woman. Currently, 1 in 5 stay-at-home parents in the United States are fathers (Fry, 2023). When a parent is available for childcare, finances are not required for outside childcare, and significantly more family income is kept within the home. Future employment options for the stay-at-home parent may be limited when they return to the workforce because employers can view a significant gap in work history negatively.
Single-Parent Family
Single-parent families are defined as children living with one parent. Nearly 24 million children in the United States live in a single-parent home, and 14.5 million of those children live in a mother-only household (The Annie E. Casey Foundation, 2023). According to The Annie E. Casey Foundation (2023), nearly 30 percent of single parents live in poverty compared to only 6 percent of married couples; the children of these parents experience more physical, mental, and behavioral problems due to growing up poor. This foundation emphasizes that single-parent families also have strengths and benefits, such as the parent being able to focus on the children rather than dividing their attention between children and a significant other. In the case of divorce from a violent partner, violence or anger is resolved, and the stress of violence is greatly reduced (Ratini, 2023). In the health-care setting, the nurse should make sure that the parent who is present with the child is the legal guardian prior to discussing health-care information, and documentation should include this information.
Extended Family
An extended family consists of grandparents, aunts, uncles, and cousins. In some cultures, the nuclear family lives in the same house as their extended family. Many families struggling financially will live in one house to save money. Other families move grandparents into their home due to their failing health. Nurses caring for a person with extended family in the room should ask the person if they desire their extended family to be included in their plan of care prior to discussing private health-care information.
Blended or Binuclear Family
A blended famil y, also known as a binuclear or stepfamily, consists of parents and children who are not biologically related to the other parent. A blended family is usually created after a death or divorce but can also include those who have never married. According to the Step Family Foundation (n.d.), more than 50 percent of U.S. families are remarried or recoupled. Children of blended families may have trouble adjusting to their new parent and siblings. They may feel their new stepparent is trying to replace their other parent. Stepparents may feel the stepchild is not giving them a chance to be a family. Blended families can cause stress for the parents and children. Nurses should be aware of family stress as they are caring for a person.
Foster Care: Children’s Aid
Foster care is a service provided by states that provides temporary homes to children who cannot live with their families. Different states offer different foster care programs. New York has a program called Children’s Aid foster care. This program is unique because it places children with families in their neighborhood to maintain relationships and familiar surroundings, such as school, church families, friends, and support systems. Children’s Aid currently has 500 to 600 children and young people in stable homes in their own neighborhoods across New York. If the birth family is unable to reunite with the child, Children’s Aid will help in the adoption process with a new family.
For more information, visit the Children’s Aid website.
Care of LGBTQIA+ Persons and Families
The biggest barrier to accessing culturally competent health care for LGBTQIA+ families is the lack of knowledge on the part of health-care providers. Providers and nurses may find themselves confused about pronouns, terminology, how to provide gender-affirming care, and what professional guidelines are specific to transgender and gender-nonconforming persons. Table 2.1 lists some current LGBTQIA+ terminology.
| Terminology | Definition |
|---|---|
| Transgender | An umbrella term for a person whose gender identity and gender expression may differ from the gender they were assigned at birth |
| LGBTQIA+ | Lesbian, gay, bisexual, transgender, queer or questioning, intersex, asexual, and any other identity |
| Bisexual | A person who is attracted to people with male and female gender identities |
| Cisgender | A person whose gender identity matches the sex they were assigned at birth |
| Gender affirmation | The process of aligning gender expression, social perception, and physical appearance with gender identity |
| Gender expression | The way a person communicates gender identity through behavior and/or appearance |
| Gender identity | A person’s internal sense of their gender; being male, female, or both male and female, neither male nor female, or something else |
| Gender nonconforming | People whose gender does not fit within traditional expectations of masculinity and femininity; this can include identities such as gender fluid, gender expansive, and gender queer |
| Queer | Any sexual orientation that is not straight or any gender identity that is not cisgender |
| Sexual orientation | A person’s emotional, romantic, or sexual attraction to other people |
| Transfeminine | A person assigned male at birth identifying as trans/nonbinary |
| Transgender man | A person with a male gender identity who was assigned female at birth |
| Transgender woman | A person with a female gender identity who was assigned male at birth |
| Transmasculine | A person assigned female at birth identifying as trans/nonbinary |
Historical Trauma
The cumulative trauma associated with a specific cultural, racial, marginalized, or ethnic group is called historical trauma . It provides a useful theory for the nurse to examine the experiences of LGBTQIA+ persons within the U.S. health-care system currently and in previous generations. When people who identify as LGBTQIA+ arrive for care, they carry the weight of discrimination that their family and friends have experienced, along with cumulative pain, bias, and mistreatment (Mirza & Roney, 2018). This leads to persons expecting to be treated with those same biases. In a 2018 survey, 8 percent of LGBTQIA+ respondents reported that a clinician refused to see them at an office visit due to their perceived sexual orientation, 7 percent reported that a clinician refused to recognize a child of a same-sex partner, 9 percent reported that a health-care provider used harsh or abusive language while treating them, and 7 percent reported experiencing unwanted physical contact from a health-care provider (such as fondling, sexual assault, or rape) (Mirza & Roney, 2018). For many LGBTQIA+ people, the health-care system continues to be perceived as an unsafe space. Using evidence-based resources, the nurse has the responsibility and power to provide culturally competent, supportive nursing care.
Using Affirming and Inclusive Language
There are many evidence-based gender-affirming interventions the nurse can implement in the clinic to improve patient outcomes and create safer spaces for the LGBTQIA+ community. Language that accurately describes a person’s gender identity, called gender-affirming language , is imperative in the health-care setting. Using inappropriate or inaccurate language to describe a person’s gender can be detrimental to the patient’s mental health, causing them to be distrustful of the nurse, health-care providers, and the health-care system as a whole (Dawson & Leong, 2020). Health-care offices and hospitals can add gender-affirming language to intake forms, ask which pronouns the patient prefers, ask the patient’s gender identity, or ask how they identify. Nurses can introduce themselves and provide the pronouns they prefer, then ask the patient their preferred pronouns. Nurses should remember that words can heal. By using appropriate gender-affirming language, the nurse can establish trust and provide supportive care.
Safe Health-Care Spaces
Health-care offices and hospitals must consider if the environment they provide is inclusive of all persons. Language used in electronic health records or office paperwork should also be gender affirming or gender neutral. Check-in logs should provide choices beyond male or female for gender identity. Relationship status should also be inclusive. Nurses can advocate for safe spaces for all patients, including having a private physical space to allow private disclosure of a person’s gender identity, sexual orientation, sex assigned at birth, and preferred pronouns. The nurse can also advocate for independent electronic health record tablets to be used independently by the patient to disclose this information (Deutsch & Buchholz, 2015). The nurse can play an important role in advocating for and integrating diverse, equitable, and inclusive care throughout the office and hospital.
LGBTQIA+ Images in Offices and Hospitals
Another way to ensure diverse, equitable, and inclusive care for all patients is by including images of people and families that look like them. The nurse can advocate for updated illustrations and educational materials reflecting gender-affirming language and LGBTQIA+-friendly materials. In 2014, the Gay & Lesbian Medical Association released a guideline for clinicians to create safer spaces for LGBTQIA+ persons. The guidelines stated that LGBTQIA+ persons often “scan” the office for cues that they are welcome; those cues include rainbow flags, unisex bathrooms, and even small LGBTQIA+ stickers or symbols. The guidelines also recommended exhibiting posters of racially and ethnically diverse same-sex couples or transgender people, along with posters from nonprofit LGBTQIA+ and HIV/AIDS organizations.
Affirmative Language in Charting Systems
The electronic health record (EHR) is one of the biggest areas of discrimination for LGBTQIA+ patients. Most EHRs contribute to microaggressions long before the person even meets the clinician. EHRs are not programmed to accommodate diverse options for a person’s gender identity, chosen name, or preferred pronouns. Imagine a transgender man giving birth in a labor and delivery unit, repeatedly asking that the gender on his wristband be changed to male and being told that the EHR could not accommodate that. Deficits like this cause people to feel invisible to clinicians and deny them access to the care they desire and deserve. Additionally, being misidentified can cause a patient posttraumatic stress, depression, and anxiety.
The EHR should also be updated to allow patients to choose or enter the descriptors that apply to them. Recently, the Human Rights Campaign (2018) found that less than 50 percent of health-care facilities in the United States have specific policies ensuring appropriate, welcoming interactions with transgender persons. Nurses can advocate for their hospital to provide LGBTQIA+ persons appropriate care in a safe, protected environment such as maternal health units.
Family Planning for the LGBTQIA+ Family
All people who have a uterus should be offered full reproductive care including preconception, pregnancy, contraceptive, and abortion care (Dawson & Leong, 2020). One issue faced by LGBTQIA+ persons is that few facilities provide care specific to their community, including fertility preservation services (Dawson & Leong, 2020). Fertility preservation is the process of freezing embryos, eggs, ovarian tissue, sperm, or testicular tissue for future reproduction. According to a study conducted by Jones et al. (2020) on nonhospital facilities providing abortion care, estimates suggest 462 to 530 transgender people obtained abortions primarily at facilities that did not provide transgender-specific health care. Additionally, recent surveys suggest that in most states, 20 to 30 percent of LGBTQIA+ persons are raising children (Movement Advancement Project, 2024). Nurses may care for LGBTQIA+ persons who are making a family via adoption, use of a surrogate, or pregnancy through artificial insemination.
In addition to planned pregnancies, LGBTQIA+ patients can experience unplanned pregnancies as a result of consensual sex and sexual assaults. Data suggest that LGBTQIA+ people experience sexual assault at higher rates than cisgender and heterosexual people (Human Rights Campaign, 2022.). Therefore, sexual assault nurse examiners (SANE) and emergency department staff must be culturally competent to care for survivors who are LGBTQIA+.
The National LGBT Health Education Center , a part of the Program of the Fenway Institute, is an interdisciplinary center for research, education, training, and policy development for LGBTQIA+ people. They have created best practices that nurses can use to update guidelines in clinics and hospitals for transgender and gender-nonconforming patients in a free downloadable document.
Challenges in Caring for Families
Clear and effective communication between the patient and the nursing professional is essential. Communication can be hindered by a language barrier. Quality nursing care can be negatively affected by not supplying language-appropriate resources in the form of medical interpreters and printed health information in a patient’s native language.
Different Languages
Culturally and linguistically appropriate services (CLAS) are “respectful of and responsive to the health beliefs , practices and needs of diverse patients” (Culturally and Linguistically Appropriate Services, 2023, p. 1). Language-appropriate health care provides care in the person’s native language. The Agency for Healthcare Research and Quality defines linguistic competence as “providing readily available, culturally appropriate oral and written language services to limited English proficiency (LEP) members through such means as bilingual/bicultural staff, trained medical interpreters, and qualified translators” (“What Is Cultural and Linguistic Competence?” 2019, p. 1).
All educational materials, instructions, and consent forms should be offered in the patient’s preferred language. When caring for a person whose primary language is not English and who has a limited ability to speak, read, write, or understand the English language, the nurse should seek the services of a trained medical interpreter. The Joint Commission (2021) requires that interpretative services be provided by trained bilingual staff, contracted interpreting services, or employed language interpreters. The requirement states that if the health-care provider is bilingual and communicates with the patient in their preferred language, an interpreter is not needed.
Nurses should refrain from asking a patient’s family member to act as an interpreter. The patient may withhold sensitive information from them, or family members may possibly edit or change the information provided. Unfamiliarity with medical terminology can also cause misunderstanding and errors.
Medical interpreters may be on-site or available by videoconferencing or telephone. The nurse should also consider coordinating patient and family member conversations with other health-care team members to streamline communication, while being aware of cultural implications such as who can discuss what health-care topics and who makes the decisions. When possible, the nurse should obtain a medical interpreter of the same gender as the patient to prevent potential embarrassment if a sensitive matter is being discussed.
Guidelines for Working with a Medical Interpreter
- Allow extra time for the interview or conversation with the patient.
- Whenever possible, meet with the interpreter beforehand to provide background.
- Document the name of the medical interpreter in the progress note.
- Always face and address the patient directly, using a normal tone of voice. Do not direct questions or conversation to the interpreter.
- Speak in the first person (using “I”).
- Avoid using idioms, such as, “Are you feeling under the weather today?” Also avoid abbreviations, slang, jokes, and jargon.
- Speak in short paragraphs or sentences. Ask only one question at a time. Allow sufficient time for the interpreter to finish interpreting before beginning another statement or topic.
- Ask the patient to repeat any instructions and explanations given to verify that they understood.
Disability
Culturally competent care also applies to those with physical and intellectual disabilities. For pregnant or laboring persons with disabilities , the nurse must work with the person to determine a plan of care that meets their needs and respects their uniqueness (Schnaith et al., 2021). For example, among U.S. women aged 18 to 39, approximately 4.7 percent experience hearing loss; pregnant persons who are hard-of-hearing can experience adverse health outcomes due to inadequate communication (Mitra et al., 2020). Nurses should be aware that this population has higher rates of chronic conditions and pregnancy complications (preterm birth and low birth weight) (Mitra et al., 2020). The nurse needs to determine if the patient is verbal and, if not, determine how the patient best communicates. If the patient is deaf, the nurse should use an American Sign Language interpreter to discuss health history and expectations for labor and birth.
For people who are visually impaired, pregnancy brings different challenges. To assist the person, the nurse can provide a tour of the labor and birth unit, allowing the person to become familiar with the surroundings. Health-care providers and nurses should always introduce themselves due to the patient’s inability to read their name tag. Other actions to consider are to warn the patient you are about to touch them, announce yourself when entering the room, and announce that you are leaving the room (Jillings, 2017). Written information should be available in Braille or by audio. To assist with care of the newborn, the nurse can describe the newborn’s facial expressions or behaviors in response to certain interventions.
Nursing care for persons with physical disabilities is tailored for their specific needs. Hospitals, offices, and clinics should have wheelchair access to the facility, bathrooms with bars and wheelchair access, wide doors, and exam tables that are easily accessible for those with physical disabilities (Figure 2.2). The nurse should ask the person which activities require assistance and which do not, respecting the person’s independence but providing help when needed. The nurse can also order special equipment such as a bedside commode or shower chair to make daily activities easier for the person. During birth, the nurse can assist the person into a position that is easiest and most comfortable to the birthing person.
Mayo Clinic provides information regarding care of the pregnant person with disabilities for patients. The website provides information on navigating the health-care system, finding support before and after birth, getting financial help, and understanding the rights of parents with disabilities.
Culture
The set of norms, attitudes, and beliefs that a group of people accept and pass along to the next generation is called culture . Many cultures have beliefs that explain what causes illness, how illnesses can be treated or cured, and who should be involved in the process. Culture also affects how people communicate with providers in terms of language or eye contact or what can be discussed in terms of the person’s body, health, or illness. A person’s culture affects everything from how they think and feel about health and illness, to how receptive they are to treatment recommendations, to how, when, and from whom they receive care.
Spirituality and Religion
Throughout history, spirituality , religion, and health have often gone together. Spirituality and religion are not the same, however. Spirituality is what a person feels and believes that brings that person peace and understanding of the meaning of life. It is important to ask the patient how they nurture their spirit. Religion is a belief system that is practiced as a group or community. In many healing traditions, healers also serve as religious leaders. Many people rely on their religious and spiritual beliefs when making medical decisions. For instance, Jehovah’s Witnesses believe that it is against God’s will to accept blood products and will therefore not allow blood transfusions. A person’s religious beliefs can affect their dietary intake. For example, many people following the religions of Hinduism, Jainism, and Buddhism are vegetarian (Tesfamariam, 2020). Health-care providers must be prepared to take patients’ religious and spiritual preferences into account as an important part of the treatment plan (Swihart et al., 2022). A thorough cultural assessment should include information on a patient’s religious and spiritual beliefs that might affect their care.
Adolescent Parenthood in Western Cultures versus Other Cultures
According to the National Vital Statistics Reports (Centers for Disease Control and Prevention [CDC], 2022), the U.S. teen birth rate was 15.4 per 1,000 females ages 15 to 19 in 2020, which was down 8 percent from 2019 and 75 percent from 1991. Factors associated with teen pregnancy and birth in the United States are having a mother who gave birth as a teen and had lower levels of education; not feeling connected with family; living in communities with higher rates of substance misuse, violence, and hunger; and being Black or Hispanic and having less access to family planning services and information and more distrust due to mistreatment by the medical community (U.S. Department of Health & Human Services, n.d.-a).
In other countries, such as Ghana, where 20 percent of girls become pregnant before the age of 18, adolescent pregnancy is associated with health risks and social and economic hardships for adolescents, families, the community, and society (Amoadu et al., 2022). An estimated 21 million adolescent girls become pregnant annually in developing countries, and 12 million below the age of 16 give birth (Amoadu et al., 2022). In Ghana, confounding factors include lack of knowledge about or accessibility of contraception.  Adolescent pregnancies in the United States are associated with higher incidences of violence in marriage, decreased education and employment opportunities, social stigma, and rejection from parents and communities.


5.6: Equivalent Statements
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Learning Objectives
After completing this section, you should be able to:
- Determine whether two statements are logically equivalent using a truth table.
- Compose the converse, inverse, and contrapositive of a conditional statement
Have you ever had a conversation with or sent a note to someone, only to have them misunderstand what you intended to convey? The way you choose to express your ideas can be as, or even more, important than what you are saying. If your goal is to convince someone that what you are saying is correct, you will not want to alienate them by choosing your words poorly.
Logical arguments can be stated in many different ways that still ultimately result in the same valid conclusion. Part of the art of constructing a persuasive argument is knowing how to arrange the facts and conclusion to elicit the desired response from the intended audience.
In this section, you will learn how to determine whether two statements are logically equivalent using truth tables, and then you will apply this knowledge to compose logically equivalent forms of the conditional statement. Developing this skill will provide the additional skills and knowledge needed to construct well-reasoned, persuasive arguments that can be customized to address specific audiences.
Checkpoint
An alternate way to think about logical equivalence is that the truth values have to match. That is, whenever is true, is also true, and whenever is false, is also false.
Determine Logical Equivalence
Two statements, and , are logically equivalent when is a valid argument, or when the last column of the truth table consists of only true values. When a logical statement is always true, it is known as a tautology . To determine whether two statements and are logically equivalent, construct a truth table for and determine whether it valid. If the last column is all true, the argument is a tautology, it is valid, and is logically equivalent to ; otherwise, is not logically equivalent to .
Exercise \(\PageIndex{1}\): Determining Logical Equivalence with a Truth Table
Create a truth table to determine whether the following compound statements are logically equivalent.
- Answer
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1. Construct a truth table for the biconditional formed by using the first statement as the hypothesis and the second statement as the conclusion, ( p → q ) ↔ ( ~ p → ~ q ).

2. Construct a truth table for the biconditional formed by using the first statement as the hypothesis and the second statement as the conclusion,
( p → q) ↔ ( ~ p ∨ q ) .T T T F T T T F F F F T F T T T T T F F T T T T Because the last column is true for every entry, the biconditional is valid and the statement is logically equivalent to the statement . Symbolically,
Your Turn \(\PageIndex{1}\)
Create a truth table to determine whether the following compound statements are logically equivalent.
1. \(p \rightarrow q ; q \rightarrow \sim p\)
2. \(p \rightarrow q ; p \vee \sim q\)
Compose the Converse, Inverse, and Contrapositive of a Conditional Statement
The converse , inverse , and contrapositive are variations of the conditional statement,
- The converse is if then , and it is formed by interchanging the hypothesis and the conclusion. The converse is logically equivalent to the inverse.
- The inverse is if then , and it is formed by negating both the hypothesis and the conclusion. The inverse is logically equivalent to the converse.
- The contrapositive is if then , and it is formed by interchanging and negating both the hypothesis and the conclusion. The contrapositive is logically equivalent to the conditional.
The table below shows how these variations are presented symbolically.
| Conditional | Contrapositive | Converse | Inverse | ||||
|---|---|---|---|---|---|---|---|
| T | T | F | F | T | T | T | T |
| T | F | F | T | F | F | T | T |
| F | T | T | F | T | T | F | F |
| F | F | T | T | T | T | T | T |
Exercise \(\PageIndex{2}\): Writing the Converse, Inverse, and Contrapositive of a Conditional Statement
Use the statements, : Harry is a wizard and : Hermione is a witch, to write the following statements:
- Write the conditional statement, , in words.
- Write the converse statement, , in words.
- Write the inverse statement, , in words.
- Write the contrapositive statement, , in words.
- Answer
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- The conditional statement takes the form, “if p p , then q q ,” so the conditional statement is: “If Harry is a wizard, then Hermione is a witch.” Remember the if … then … words are the connectives that form the conditional statement.
- The converse swaps or interchanges the hypothesis, p p , with the conclusion, q q . It has the form, “if q q , then p p .” So, the converse is: "If Hermione is a witch, then Harry is a wizard."
- To construct the inverse of a statement, negate both the hypothesis and the conclusion. The inverse has the form, “if ~ p ~ p , then ~ q ~ q ,” so the inverse is: "If Harry is not a wizard, then Hermione is not a witch."
- The contrapositive is formed by negating and interchanging both the hypothesis and conclusion. It has the form, “if ~ q ~ q , then ~ p ~ p ," so the contrapositive statement is: "If Hermione is not a witch, then Harry is not a wizard."
Your Turn \(\PageIndex{2}\)
Use the statements, \(p\) : Elvis Presley wore capes and \(q\) : Some superheroes wear capes, to write the following statements:
1. Write the conditional statement, \(p \rightarrow q\), in words.
2. Write the converse statement, \(q \rightarrow p\), in words.
3. Write the inverse statement, \(\sim p \rightarrow \sim q\), in words.
4. Write the contrapositive statement, \(\sim q \rightarrow \sim p\), in words.
Exercise \(\PageIndex{3}\)
Use the conditional statement, “If all dogs bark, then Lassie likes to bark,” to identify the following.
- Write the hypothesis of the conditional statement and label it with a .
- Write the conclusion of the conditional statement and label it with a .
- Identify the following statement as the converse, inverse, or contrapositive: “If Lassie likes to bark, then all dogs bark.”
- Identify the following statement as the converse, inverse, or contrapositive: “If Lassie does not like to bark, then some dogs do not bark.”
- Which statement is logically equivalent to the conditional statement?
- Answer
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- The hypothesis is the phrase following the if . The answer is p : All dogs bark. Notice, the word if is not included as part of the hypothesis.
- The conclusion of a conditional statement is the phrase following the then . The word then is not included when stating the conclusion. The answer is: q: Lassie likes to bark.
- “Lassie likes to bark” is q and “All dogs bark” is p . So, “If Lassie likes to bark, then all dogs bark,” has the form “if q , then p ,” which is the form of the converse. “Lassie does not like to bark” is ~ q and “Some dogs do not bark” is ~ p . The statement, “If Lassie does not like to bark, then some dogs do not bark,” has the form “if ~ q , then ~ p ,” which is the form of the contrapositive.
- The contrapositive ~ q → ~ p is logically equivalent to the conditional statement p → q .
Your Turn \(\PageIndex{3}\)
Use the conditional statement, “If Dora is an explorer, then Boots is a monkey,” to identify the following:
1 . Write the hypothesis of the conditional statement and label it with a p�.
2 . Write the conclusion of the conditional statement and label it with a q�.
3 . Identify the following statement as the converse, inverse, or contrapositive: “If Dora is not an explorer, then Boots is not a monkey.”
4 . Identify the following statement as the converse, inverse, or contrapositive: “If Boots is a monkey, then Dora is an explorer.”
5 . Which statement is logically equivalent to the inverse?
Exercise \(\PageIndex{4}\)
Assume the conditional statement, p→q: “If Chadwick Boseman was an actor, then Chadwick Boseman did not star in the movie Black Panther ” is false, and use it to answer the following questions.
- Write the converse of the statement in words and determine its truth value.
- Write the inverse of the statement in words and determine its truth value.
- Write the contrapositive of the statement in words and determine its truth value.
- Answer
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The only way the conditional statement can be false is if the hypothesis, p : Chadwick Boseman was an actor, is true and the conclusion, q: Chadwick Boseman did not star in the movie Black Panther , is false. The converse is q → p, and it is written in words as: “If Chadwick Boseman did not star in the movie Black Panther , then Chadwick Boseman was an actor.” This statement is true, because false → true is true.
The inverse has the form “ ~ p → ~ q. ” The written form is: “If Chadwick Boseman was not an actor, then Chadwick Boseman starred in the movie Black Panther .” Because p is true, and q is false, ~ p is false, and ~ q is true. This means the inverse is false → true, which is true. Alternatively, from Question 1, the converse is true, and because the inverse is logically equivalent to the converse it must also be true.
The contrapositive is logically equivalent to the conditional. Because the conditional is false, the contrapositive is also false. This can be confirmed by looking at the truth values of the contrapositive statement. The contrapositive has the form “ ~ q → ~ p. ” Because q is false and p is true, ~ q is true and ~ p is false. Therefore, ~ q → ~ p is true → false, which is false. The written form of the contrapositive is “If Chadwick Boseman starred in the movie Black Panther , then Chadwick Boseman was not an actor.”
Your Turn \(\PageIndex{4}\)
Assume the conditional statement p→q : “If my friend lives in San Francisco, then my friend does not live in California” is false, and use it to answer the following questions.
1 . Write the converse of the statement in words and determine its truth value.
2 . Write the inverse of the statement in words and determine its truth value.
3 . Write the contrapositive of the statement in words and determine its truth value.
Check Your Understanding
- Two statements \(p\) and \(q\) are logically equivalent to each other if the biconditional statement, \(p \leftrightarrow q\) is ________________.
- The _____ statement has the form, “\(p\) then \(q\).”
- The contrapositive is _____________ ___________ to the conditional statement, and has the form, "if \(\text~q\), then \(\text~p\)."
- The _________________ of the conditional statement has the form, "if \(\text~p\), then \(\text~q\)."
- The _________________ of the conditional statement is logically equivalent to the _______________ and has the form, "if \(q\) then \(p\)."


17.2: Reflective Learning
Reflective thinking is a powerful learning tool. As we have seen throughout this course, proficient readers are reflective readers, constantly stepping back from the learning process to think about their reading. They understand that just as they need to activate prior knowledge at the beginning of a learning task and monitor their progress as they learn, they also need to make time during learning as well as at the end of learning to think about their learning process, to recognize what they have accomplished, how they have accomplished it, and set goals for future learning. This process of “thinking about thinking” is called metacognition. When we think about our thinking—articulating what we now know and how we came to know it—we close the loop in the learning process.
How do we engage in reflection? Educator Peter Pappas modified Bloom’s Taxonomy of Learning to focus on reflection:
This “taxonomy of reflection” provides a structure for metacognition. Educator Silvia Rosenthal Tolisano has modified Pappas’s taxonomy into a pyramid and expanded upon his reflection questions:
Use Pappas’s and Tolisano’s taxonomies of reflection to help you reflect on your learning, growth and development as a reader, writer, and thinker in this course.
Contributors and Attributions
- Composition II. Authored by : Elisabeth Ellington, Ph.D.. Provided by : Chadron State College. Located at : http://www.csc.edu/ . Project : Kaleidoscope Open Course Initiative. License : CC BY: Attribution
- Image of Taxonomy. Authored by : Peter Pappas. Located at : http://www.peterpappas.com/images/2011/08/taxonomy-of-reflection.png . Project : Copy/Paste. License : CC BY-NC: Attribution-NonCommercial
- Image of pyramid. Authored by : Silvia Rosenthal Tolisano. Located at : langwitches.org/blog/2011/06/20/reflectu00adreflectingu00adreflection/. License : CC BY-NC-SA: Attribution-NonCommercial-ShareAlike


13.9: Credit Spreads
Credit Spreads represent the i ncremental yield provided to compensate for additional default risk above a no-risk alternative (Treasury Notes), and for a given maturity – usually 10-years. We have drawn in the yield curves for Treasuries and “B”-rated Corporates. The Credit Spread below is represented by the difference in yields between points “B” and “T.”
Questions
:
Which companies issue credit ratings?
What are the important credit ratings?
What do “Investment Grade” and “Junk” or “High-Yield” Bonds mean?
Reality Check : Credit spreads are not constant. During weak economic periods, credit spreads widen, in response to fear of the perceived risks associated with lower-rated bonds. In fact, default rates themselves may not worsen, but still, people get nervous. In such times, people demand more premium return versus Treasuries than before.
How exactly does this happen? Many will sell their lower-rated bonds and buy Treasuries with the sale proceeds. Lower-rated bonds’ prices therefore fall and their yields rise; Treasury prices rise, and yields go down. Credit spreads widen. Remember that price and yield (i.e., discount rates) are inversely related. This does not say that actual credits, i.e., default risks, have worsened; that may or may not eventually happen. A bond may be considered a “credit.” This phenomenon – whereby credit spreads widen – is referred to as a flight to quality .
Below we illustrate the flight to quality.
The Flight to Quality
Yields
Above, in anticipation of weak times ahead, Credit Spreads widen from B 0 less T 0 to B 1 less T 1 . That does not imply that default rates have worsened in reality, although, in time, as conditions worsen, that could happen as well.
When rates increased between 1978 and 1982, the spread between (Ten-Year) Treasuries and Baa Corporate Bonds widened. Baa and BBB bondholders lost money in part due to increased rates and, in addition, due to a widening of the spread (such bondholders would have lost less in Treasuries).
Credit spreads were wide when the technology “bubble” burst in 2000-2001. Greater credit spreads reduce corporations’ ability to borrow and thus serve to dampen economic growth.
Just prior to the Banking Crisis of 2007-2008, Credit Spreads were very narrow by historical standards. To some prognosticators, the optimism implicit in such narrow spreads boded ill for near-term economic conditions. They were right.
Many things can happen that may interact with credit spreads, including moves up or down in the entire yield curve. What is important to recognize, at the base level, is that lower grade bonds – and their yields – are (usually) priced relative to Treasuries, i.e., at some premium to Treasury yields. The lower the credit rating, the greater the impact of “nervousness” on yield.
For a graph of historical credit spreads, click on: Bond Yield Credit Spreads – 150 Year Chart | Longtermtrends


3.8: Proteins - Building Blocks
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- Ying Liu
- City College of San Francisco
Learning Objectives
- Describe the fundamental structure of an amino acid
- Describe the chemical structures of proteins
- Summarize the unique characteristics of proteins
At the beginning of this chapter, a famous experiment was described in which scientists synthesized amino acids under conditions simulating those present on earth long before the evolution of life as we know it. These compounds are capable of bonding together in essentially any number, yielding molecules of essentially any size that possess a wide array of physical and chemical properties and perform numerous functions vital to all organisms. The molecules derived from amino acids can function as structural components of cells and subcellular entities, as sources of nutrients, as atom- and energy-storage reservoirs, and as functional species such as hormones, enzymes, receptors, and transport molecules.
Amino Acids and Peptide Bonds
An amino acid is an organic molecule in which a hydrogen atom, a carboxyl group (–COOH), and an amino group (–NH 2 ) are all bonded to the same carbon atom, the so-called α carbon. The fourth group bonded to the α carbon varies among the different amino acids and is called a residue or a side chain, represented in structural formulas by the letter R . A residue is a monomer that results when two or more amino acids combine and remove water molecules. The primary structure of a protein, a peptide chain, is made of amino acid residues. The unique characteristics of the functional groups and R groups allow these components of the amino acids to form hydrogen, ionic, and disulfide bonds, along with polar/nonpolar interactions needed to form secondary, tertiary, and quaternary protein structures. These groups are composed primarily of carbon, hydrogen, oxygen, nitrogen, and sulfur, in the form of hydrocarbons, acids, amides, alcohols, and amines. A few examples illustrating these possibilities are provided in Figure \(\PageIndex{1}\).
Amino acids may chemically bond together by reaction of the carboxylic acid group of one molecule with the amine group of another. This reaction forms a peptide bond and a water molecule and is another example of dehydration synthesis (Figure \(\PageIndex{2}\)). Molecules formed by chemically linking relatively modest numbers of amino acids (approximately 50 or fewer) are called peptides, and prefixes are often used to specify these numbers: dipeptides (two amino acids), tripeptides (three amino acids), and so forth. More generally, the approximate number of amino acids is designated: oligopeptides are formed by joining up to approximately 20 amino acids, whereas polypeptides are synthesized from up to approximately 50 amino acids. When the number of amino acids linked together becomes very large, or when multiple polypeptides are used as building subunits, the macromolecules that result are called proteins. The continuously variable length (the number of monomers) of these biopolymers, along with the variety of possible R groups on each amino acid, allows for a nearly unlimited diversity in the types of proteins that may be formed.
Exercise \(\PageIndex{1}\)
How many amino acids are in polypeptides?


5.1: Lesson 5.1: Memory Model and Techniques
An Information Processing Model
UNIT 5, EXERCISE 1.1
While reading through the article linked here, “
Atkinson-Shiffrin model of memory
” answer the following questions.
SENSORY INPUT
1. If you are just walking along somewhere and pass by the usual sights, sounds, smells, etc., about how long do you think you would remember what you just took in by your senses? (Note: nothing out of the ordinary happens.)
2. If you do nothing at all to help you remember what you just took in by your senses, about how many discrete units (pieces) of data (or input, i.e., sights, sounds, smells, etc.) would you be able to remember for the brief period of time?
WORKING MEMORY (ALSO KNOWN AS SHORT TERM MEMORY)
3. Now, If you immediately begin to try to remember the input for later (for example, you notice you just passed a shop you’ve been meaning to go to, or you smell something really good coming from a restaurant that reminds you of something you like), about how many items could you then remember?
4. How long could you keep them in your memory by just using one or two memory techniques, such as associating them with something (like a memory)?
LONG TERM MEMORY
5. About how many items can you keep in your “permanent” memory storage?
6. How long can you keep them there?
RELATED QUESTIONS
7. Why is “cramming” new information the night before a test not a good idea? Go beyond the information in the article to common sense issues.


2.13: Water - Heat of Vaporization
- Explain how heat of vaporization is related to the boiling point of water
Water in its liquid form has an unusually high boiling point temperature, a value close to 100°C. As a result of the network of hydrogen bonding present between water molecules, a high input of energy is required to transform one gram of liquid water into water vapor, an energy requirement called the heat of vaporization. Water has a heat of vaporization value of 40.65 kJ/mol. A considerable amount of heat energy (586 calories) is required to accomplish this change in water. This process occurs on the surface of water. As liquid water heats up, hydrogen bonding makes it difficult to separate the water molecules from each other, which is required for it to enter its gaseous phase (steam). As a result, water acts as a heat sink, or heat reservoir, and requires much more heat to boil than does a liquid such as ethanol (grain alcohol), whose hydrogen bonding with other ethanol molecules is weaker than water’s hydrogen bonding. Eventually, as water reaches its boiling point of 100° Celsius (212° Fahrenheit), the heat is able to break the hydrogen bonds between the water molecules, and the kinetic energy (motion) between the water molecules allows them to escape from the liquid as a gas. Even when below its boiling point, water’s individual molecules acquire enough energy from each other such that some surface water molecules can escape and vaporize; this process is known as evaporation.
The fact that hydrogen bonds need to be broken for water to evaporate means that a substantial amount of energy is used in the process. As the water evaporates, energy is taken up by the process, cooling the environment where the evaporation is taking place. In many living organisms, including humans, the evaporation of sweat, which is 90 percent water, allows the organism to cool so that homeostasis of body temperature can be maintained.
Key Points
- The dissociation of liquid water molecules, which changes the substance to a gas, requires a lot of energy.
- The boiling point of water is the temperature in which there is enough energy to break the hydrogen bonds between water molecules.
- Water is converted from its liquid form to its gaseous form (steam) when the heat of vaporization is reached.
- Evaporation of sweat (mostly water) removes heat from the surface of skin, cooling the body.
Key Terms
- heat of vaporization : The energy required to transform a given quantity of a substance from a liquid into a gas at a given pressure (often atmospheric pressure).


11.1: Lymphatic and Immune Systems Introduction
Learning Objectives
- Apply the rules of medical language to build, analyze, spell, pronounce, abbreviate, and define terms as they relate to the lymphatic and immune systems
- Identify meanings of key word components of the lymphatic and immune systems
- Categorize diagnostic, therapeutic, procedural, or anatomic terms related to the lymphatic and immune systems
- Use terms related to the lymphatic and immune systems
- Use terms related to the diseases and disorders of the lymphatic and immune systems
Introduction to the Lymphatic and Immune Systems
The lymphatic system is a network of organs, lymph nodes, lymph ducts, and lymph vessels that produce and transport lymph from tissue spaces to the bloodstream. The lymphatic system is a major part of the body’s immune system. [1]
This chapter will review common word components related to the lymphatic and immune systems to assist learners in analyzing, building, and defining medical terms. Other terms, whose definitions cannot be easily built from word components, will be described in context based on the anatomy and physiology of the lymphatic and immune systems and common diseases and disorders. Because the lymphatic system shares organs with a number of other body systems, the disorders discussed near the end of this chapter mainly focus on disorders of the immune system. Medical specialists, diagnostic tests, and procedures related to the lymphatic and immune systems will also be discussed.
View the following YouTube video [2] for an overview of the lymphatic system: Lymphatic System: Crash Course A&P #44
- A.D.A.M. Medical Encyclopedia [Internet]. Atlanta (GA): A.D.A.M., Inc.; c1997-2023. Lymph system; [reviewed 2022, Jul 25; cited 2023, Nov 5). https://medlineplus.gov/ency/article/002247.htm ↵
- CrashCourse. (2015, November 30). Lymphatic system: Crash Course A&P #44 [Video]. YouTube. All rights reserved. https://www.youtube.com/watch?v=I7orwMgTQ5I&feature=youtu.be ↵


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7.2.1: Energy and Metabolism
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Cells perform the functions of life through various chemical reactions. A cell’s metabolism refers to the combination of chemical reactions that take place within it. Catabolic reactions break down complex chemicals into simpler ones and are associated with energy release. Anabolic processes build complex molecules out of simpler ones and require energy. In studying energy, the term system refers to the matter and environment involved in energy transfers.
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7.2.2: Glycolysis
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ATP functions as the energy currency for cells. It allows cells to store energy briefly and transport it within itself to support endergonic chemical reactions. The structure of ATP is that of an RNA nucleotide with three phosphate groups attached. As ATP is used for energy, a phosphate group is detached, and ADP is produced. Energy derived from glucose catabolism is used to recharge ADP into ATP. Glycolysis is the first pathway used in the breakdown of glucose to extract energy.
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7.2.3: Citric Acid Cycle and Oxidative Phosphorylation
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The citric acid cycle is a series of chemical reactions that removes high-energy electrons and uses them in the electron transport chain to generate ATP. One molecule of ATP (or an equivalent) is produced per each turn of the cycle. The electron transport chain is the portion of aerobic respiration that uses free oxygen as the final electron acceptor for electrons removed from the intermediate compounds in glucose catabolism.
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7.2.4: Fermentation
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If NADH cannot be metabolized through aerobic respiration, another electron acceptor is used. Most organisms will use some form of fermentation to accomplish the regeneration of NAD+, ensuring the continuation of glycolysis. The regeneration of NAD+ in fermentation is not accompanied by ATP production; therefore, the potential for NADH to produce ATP using an electron transport chain is not utilized.
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7.2.5: Connections to Other Metabolic Pathways
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Metabolic pathways should be thought of as porous—that is, substances enter from other pathways, and other substances leave for other pathways. These pathways are not closed systems. Many of the products in a particular pathway are reactants in other pathways.
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7.2.E: How Cells Obtain Energy (Exercises)
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