7.12.4: Chapter Review
The Multiplication Rule for Counting
You are booking a round trip flight for vacation. If there are 4 outbound flight options and 7 return flight options, how many different options do you have?
You are putting together a social committee for your club. You’d like broad representation, so you will choose one person from each class. If there are 8 seniors, 12 juniors, 10 sophomores, and 6 first-years, how many committees are possible?
The Big Breakfast Platter at Jimbo’s Sausage Haus gives you your choice of 4 flavors of sausage, 5 preparations for eggs, 3 different potato options, and 4 different breads. If you choose one of each, how many different Big Breakfast Platters can be selected?
The multiple-choice quiz you’re about to take has 10 questions with 4 choices for each. How many ways are there to fill out the quiz?
Permutations
Compute \(\frac{8!}{2!3!3!}\).
Compute \(\frac{12!}{8!3!}\).
Compute \(\frac{211!}{210!}\)
Compute \(_5{P_3}\).
Compute \(_{15}{P_3}\).
Compute \(_{22}{P_5}\).
As you plan your day, you see that you have 6 tasks on your to-do list. You’ll only have time for 5 of those. How many schedules are possible for you today?
As captain of your intramural softball team, you are responsible for setting the 10-person batting order for the team. If there are 12 people on the team, how many batting orders are possible?
Combinations
If you’re trying to decide which 4 of your 12 friends to invite to your apartment for a dinner party, are you using permutations or combinations?
If you’re trying to decide which of your guests sits where at your table, are you using permutations or combinations?
Compute \(_7{C_4}\).
Compute \(_{13}{C_8}\).
How many ways are there to draw a hand of 8 cards from a deck of 16 cards?
In a card game with 4 players and a deck of 12 cards, how many ways are there to deal out the four 3-card hands?
Tree Diagrams, Tables, and Outcomes
If you draw a card at random from a standard 52-card deck and note its suit, what is the sample space?
If you draw 2 cards at random from a standard 52-card deck and note the 2 suits (without paying attention to the order), what is the sample space?
If you draw 2 Scrabble tiles in order without replacement from a bag containing E, E, L, S, what is the sample space?
If you draw 2 Scrabble tiles without replacement and ignoring order from a bag containing E, E, L, S, what is the sample space?
If you draw 2 Scrabble tiles without replacement and ignoring order from a bag containing E, E, L, S, what is the sample space?
If you draw 2 Scrabble tiles with replacement and ignoring order from a bag containing E, E, L, S, what is the sample space?
Basic Concepts of Probability
If you read that the probability of flipping 10 heads in a row is \(\frac{1}1024\), is that probability most likely theoretical, empirical, or subjective?
If someone tells you that there is a 40% chance that a Democrat wins the U.S. Presidential election in 2132, is that probability most likely theoretical, empirical, or subjective?
If your professor says that you have a 20% chance of getting an A in her class because 20% of her students historically have earned As, is that probability most likely theoretical, empirical, or subjective?

What is the probability of rolling a negative number?
What is the probability of rolling a number less than 20?
What is the probability of rolling an 11?
What is the probability of rolling a number less than 7?
What is the probability of not rolling an 11?
What is the probability of rolling a multiple of 4?
Over the last 30 years, it has rained 12 times on May 1. What empirical probability would you assign to the event "it rains next May 1"?
Probability with Permutations and Combinations
In the following exercises, you’re drawing cards from a special deck of cards containing \(2♡\), \(2\clubsuit\), \(2\diamondsuit\), \(2\spadesuit\), \(3♡\), \(3\clubsuit\), \(3\spadesuit\), \(4♡\), \(4♣\), \(5♡\).
If you draw 4 cards without replacement, what is the probability of drawing a 2, 3, 4, and 5 in order?
If you draw 4 cards without replacement, what is the probability of drawing a 2, 3, 4, and 5 in any order?
If you draw 3 cards without replacement, what is the probability that you draw a \(♡\), a \(♣\), and a \(♡\), in order?
If you draw 3 cards without replacement, what is the probability that you draw 2 \(♡\) and 1 \(♣\), in any order?
What Are the Odds?

If \(P(E) = \frac{4}{7}\), what are the odds in favor of \(E\)?
If \(P(E) = \frac{5}17\), what are the odds against \(E\)?
The Addition Rule for Probability
In the following exercises, you’re drawing a single card from a special deck of cards containing \(2♡\), \(2♣\), \(2\diamondsuit\), \(2♠\), \(3♡\), \(3♣\), \(3♠\), \(4♡\), \(4♣\), \(5♡\).
What is the probability of drawing a 2 or a 3?
What is the probability of drawing a \(♣\) or a \(♠\)?
What is the probability of drawing a 2 or a \(♡\)?
What is the probability of drawing an even number or a \(♣\)?
Conditional Probability and the Multiplication Rule
In the following exercises, you’re drawing from a special deck of cards containing \(2♡\), \(2♣\), \(2\diamondsuit\), \(2♠\), \(3♡\), \(3♣\), \(3♠\), \(4♡\), \(4♣\), \(5♡\).
If you draw a single card, what is:
- \(P({\text{draw a 2}})\)
- \(P({\text{draw a 2}}|{\text{draw a }}\heartsuit)\)
- \(P({\text{draw a 2}}|{\text{draw a }}\spadesuit )\)
If you draw a single card, what is:
- \(P({\text{draw a }}\heartsuit)\)
- \(P({\text{draw a }}\heartsuit|{\text{draw a 3}})\)
- \(P({\text{draw a }}\heartsuit|{\text{draw a 2}})\)
In the following exercises, you are playing the following game that involves rolling 2 dice, one at a time.  If the result is a 4 or less, your second roll uses a standard 4-sided die. If the result of the first roll is a 5 or 6, your second roll uses a standard 6-sided die.  If it is, identify the number of trials and the probability of success in each trial. If it isn’t, explain why it isn’t.
Draw 5 cards with replacement from a standard deck and count the number of \(♠\).
Draw 5 cards without replacement from a standard deck and count the number of \(♠\).
Draw cards from a standard deck and count how many cards are chosen before the first \(♠\) appears.
In the following exercises, you are about to roll a standard 20-sided die. Round answers to 4 decimal places.
 Give a full PDF table for the number of times a number greater than 16 appears.
If you roll the die 10 times, what is the probability that a number between 1 and 5 (inclusive) comes up exactly once?

If you roll the die 40 times, what is the probability that 20 comes up 4 or more times?
If you roll the die 100 times, what is the probability that the number of times the die lands on something less than or equal to 7 is between 30 and 35 (inclusive)?
If you roll the die 100 times, what is the probability that the number of times the die lands on something less than or equal to 7 is exactly 36?

 You win $32 if you get a sum of 12, and lose $1 otherwise. What is the expected value of this game?
Interpret your answer.
 If you roll 12 four times, you win $1,000. If you roll 12 three times, you win $100. If you roll 12 twice, you win $10. If you roll 12 one time, you don’t win or lose anything.
What is the expected value of this game?
Interpret your answer.
Which game would be better to play? Why?


14.6: Conclusion
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Terrorism, and terrorists, are transnational in three ways: their goals, their actions and their organisational form. However, we must be cautious before assuming that this is the new, and only, form of terrorism. Not all terrorism is transnational. Terrorist groups like the Irish Republican Army (IRA) and Euskadi Ta Askatasuna (ETA) still operate at the national level, targeting just one state. States too have shown themselves capable of inflicting forms of terrorism. Furthermore, while examples of transnational terrorism since 2001 may appear to be mostly religiously inspired, one cannot conclude that there is anything inevitable about this, or that Islam specifically is the significant factor. Rather, it is in this instance that Islam provides a framework for some marginal groups to construct a convincing worldwide counter-narrative to that of a world dominated by Western political, social and economic models. For that reason, it is perhaps no surprise that Islamic terrorism, over and above other types of terrorism, has become a sustained issue of concern in international relations. An important note to conclude on is that countering terrorism does not fall exclusively to the state: civil society and everyday acts by ordinary people also have a role. These can include examples of popular culture, inter-faith dialogue and moments of solidarity that break down the oppositional and binary world view that dominates transnational terrorist ideology. Nevertheless, terrorist groups are products of their time and, just like us, live in a globalised world. They are both shaped by globalisation and contribute to it by their actions.


1.7: A Theory of Emotion
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People respond negatively to pain or any negative emotion. Pain might also hinder development of emotions because it isn’t encouraging. The right factors need to be applied to someone in order to get them to experience the fullest potential of their emotions. This could simply mean having the right people around you who are supportive of you and your emotions. In fact, the words “thrive” and “support” are really key for emotion generation. That being said, it cannot be ignored that emotional events which feel painful in the short term may be beneficial in the long term, and even cause a person to thrive and experience good emotions.
It needs to be clarified what is significant about emotions, or how are they meaningful. There can be an individual emotional event, but this event might impact everything else that occurs in someone’s life. In that way everything is tied in. Even words, or therapy, might change how someone views the world and greatly influence how they experience emotion. For instance, understanding that a loved one likes you – or loves you – consciously would cause your emotions as a whole to change. So not just your understanding of that thing in specific would change, but also your experience with that person. A cliché saying that explains this would be “once you let love in, the world becomes a beautiful and sunny place”.
That expression explains the importantance of positive encouragement, the impact of one event or person on someone’s overall emotions all the time, and the importance therapy can have. That one statement might make someone realize they love someone else and what this love does for their life. [I apologize if this article is starting to sound cheesy, but it is important to realize that all emotions are tied into each other, and that small events or even your cognition (which could be influenced by therapy or words (as in the cliché example)) can greatly influence your life.] Conversely, if something very bad happens to someone, they might not care about their life anymore and start to experience all their other emotions less.
In fact, everything that happens to someone probably influences everything else that happens to that person. You could also just look at life as individual events that only have minor impacts on each other over the long term. I suppose I am asking the question, “what is everything, how does everything feel, and how does everything relate”. Is there a way to describe all emotion other than, “you’re feeling something”? Certain activities bring up certain emotions, individual circumstances and their emotional parts can be described as action-reaction relationships. If all of life is described in that way, does that explain everything? If you describe how everything feels individually then that would describe everything if you take into your account of each situation how all the other things that happened influenced how you feel for that one thing. So that means how you feel most of the time, the general emotions you have that are mostly independent of what is happening – and also how you feel for each thing that happens.
Analyzing anything, however, has many levels of complication.  That could be the first level of analysis of an event, stating the obvious emotions involved. The next level would be asking, “what are all the emotions involved”. To do that you would have to understand that all emotions are mixed, that the emotion “fun” the boy has could be mixed in with the feeling anger or frustration if he lost a fight or something. Also, how a specific negative event playing the game (say losing a battle) influenced his feelings of fun after that event. Also, his cognition might play a role, did he say something to himself after he lost to make himself feel better? Did his therapy session talking about how to deal with defeat alleviate his pain at the loss?
To have a complete understanding of everything, you could analyze the degrees of fun the boy has during the game, when it elevates and when it decreases. Is all of life like this video game, with variations of fun and anger and cognitive influences? If viewed simply, then yes, however there are many many things that happen in life that can be analyzed and the emotional components explained. It would be useful if I could describe a few principals that would apply to all of these events:
- Negative events generate fear, which causes people to either flee or shut down.
- Positive events generate pleasure, which results in encouragement and motivation.
That’s pretty much all I can think of, I suppose I could say that my theory has two parts, the pleasure instinct and the pain instinct, and that all emotions stem from these two instincts. Everything is going to generate some amount of pleasure and some amount of pain, causing reward and punishment, it is almost Pavlovian. However it is more complicated than that, while my theory works on the small individual direct event level (thing A causes you to be motivated to do thing B) it also works in small ways on everything, like one event might motivate you for something else entirely.
The pleasure and pain instincts apply when any emotion happens. Every emotion is going to be a certain amount painful, and a certain amount pleasurable. Furthermore, the meaningful aspect of the emotion is going to be how pleasurable or painful it was. Learning emotionally could be viewed as long term pleasure. So if an event is meaningful instead of just fun or pleasurable it would still be placed under the category of pleasure because this meaningful activity adds to your life overall, thus causing long-term pleasure. It is almost like intelligence is fun, only in a different more long term way. Also, an even that is fun is also going to contribute to long term intellectual emotional development as well, because a fun event is going itself to contain information, and be motivating and inspiring. That also explains why negative and painful events can be beneficial over the long run for both fun and emotional intellectual development. They can be because the event itself might communicate information to the person, or help them understand something. Almost like learning a lesson the hard way. The point is that pain or pleasure is the stimulus behind all fun, learning, and long-term fun and learning. In other words, the pain and pleasure you get from events helps you out all the time, not just for those specific events. Pleasure is inspiring and encouraging, while pain is more of a learning experience. So every emotion is going to inspire in some ways if it is pleasurable, and you might learn from painful emotions.
Pleasure and pain function in the mind in many ways. The influence emotions, thoughts and the long term conscious and unconscious impact on thoughts and emotions. There are different types of emotion and thought that are influenced by different types of pain and pleasure:
- Different types of thought can vary in how emotional they are, for instance moral decisions could involve a lot of emotion compared to simple decisions. Important thoughts about emotional things (like loved ones) might also be very emotional.
- Emotional thoughts are more intellectual pleasure than regular pleasure (because it is a thought instead of a real event).
- The more emotional the thought, the greater its long term impact and significance might be on your emotions. Like the thought "I love person x". Of course, a non-emotional thought might also have a long term impact on how much pleasure and pain you experience.
- For each different type of emotion, you could have a thought that is emotional in that way.
- Every emotion is going to be a certain type of pain or pleasure. This pain or pleasure will vary between being intellectual and emotional. The more aware you are of the pain or pleasure, the more intellectual it will be. That shows how you might be suffering or in pleasure but not know it.  There is an unconscious element of pain and pleasure. Also, the pain and pleasure, or the emotion generating those feelings, might itself be of a more intellectual type or emotional type. For instance, if you are picked on, it is because you understand that you are being insulted that results in the emotional pain. That makes the pain in part intellectual because it stems from your understanding.
- Just like every emotion is going to be a certain type of pain or pleasure, every thought is going to be as well. Like emotional thoughts or non-emotional ones.
- An insult affects emotions because you understand that it is an insult, but normal events (like working or interacting with someone) generate emotion because you have a large unconscious emotional understanding of the significance of the event. At birth they might generate emotion because that is simply how you experience emotions, however after a long time the emotion that events generate is going be based much more on your experience, and what your experience is going to teach you is how much you enjoy that event.
- The fact that thought can influence emotions, pain and pleasure is amazing if you think about it. Is a thought a real experience? Thoughts don't even last very long. However, you could think of thoughts as tied in with emotion (since thoughts can be emotional, that shows how they are real). For instance, if something bad happens, you are going to experience pain because of real reasons that could be thought about. You change the nature of the emotion by altering how you think it affected you because the emotion was really just thoughts about the event, so you change the emotion by changing the thoughts that make up the emotion.
- Since emotion is so tied in with thought, pain and pleasure can be long term because you are always thinking. Something bad might happen to you, but you unconsciously think aboout the event for a while after, causing you to experience pain.
- The type of pain and pleasure can be explained by explaining the thoughts that make up the emotion, or the emotions that make up the thoughts. Also, real events and their emotions can be explained with thoughts. It is like a real event causes a series of thoughts about the event that determine how you are going to feel about the event both during the event and after. The thoughts are so real (are based in emotion), yet only thoughts, so therefore you could control how you feel about events and how they affect you to some degree. That shows the importance of talking about your feelings. There are also learned responses which also show the importance of thoughts. The response might have been learned from thoughts or unconscious thoughts. Therefore, it could also be unlearned just by thinking.
- Thoughts can change the nature of emotion. For instance, if someone makes you happy, the more you highlight why they make you happy the more the relationship will be enhanced. Also, thoughts can direct a negative emotional response. For instance, if something bad happens to you, if you think that what happened was really bad then you might feel even worse then if you trained yourself to not care. In other words, your emotional response to events is really just an intellectual, learned response that is determined by thoughts and your thoughts over the long-term. If someone is insulted, they have learned that insults are bad over time, and that is why it makes them feel bad. It also causes them to think about the negative thing that was said, and if it is true, might make them think that they are a failure in some way. In that case, simply by thinking about the insult and why it isn't true, or why it shouldn't affect your feelings could make it so the insult doesn't carry weight the next time.
- Changing your thoughts in an attempt to change your emotions is almost like trying to change your programming because emotions are harder to control than thoughts. In the movie Terminator 3, the evil terminator changed the programming of the good terminator to kill the hero of the movie. When it was time to kill the hero, the hero tried to convince the terminator that it didn't want to kill him. The terminator struggled with back and forth switching between programming commands until it finally was able to not kill.
In review, by exploring the importance of pleasure and pain on emotion in general we gained insight into emotions, and that gave us insight into how they can be manipulated with thoughts, or your thoughts be manipulated by your emotions. So pain and pleasure function with individual thoughts as well as with emotions, that is obvious if you remember how tied in emotions are with thought - and I already explained the importance of pain on emotion. Also, thoughts can be emotional, when you think something it can bring up pain. That pain could just be an enlarged version of the pain caused by the thoughts the rest of the time (the time you're not thinking consciously of them) unconsciously. You highlight the pain by thinking about what is causing it. That might help you to change the thought, however, and therefore the unconcsious thoughts and emotions making you feel at other times.
While my pain and pleasure instincts can be applied to almost every emotional situation, there are other principals which can be applied in many situations that are almost as important as those. For instance, the social aspect of the human experience is probably one of the most important generators of emotion. You could classify everything someone does as either social or non-social, and how important and emotional can be interacting with inanimate objects? The important aspect of the social aspect, however, is personality. That is so because no matter what someone says or does, their personality is going to have a large impact on the people around them because there is an unconscious emotional interaction going on between different personalities. Of course, what someone says and does is going to be reflective of their personality, but just by describing personality types it can be inferred what that type of person would do differently. Though it is important to note that basic interactions are almost all the same, the only thing that varies is how the people have different and individual personalities and this changes the emotional interchange.
There are several things that determine what someones personality is going to be. There are important factors and non-important ones. For the principals to be general and far-reaching, I am only going to talk about the important factors. Personality could be described and the things listed be important to what that person does, and what type of intellect they have, however this would not be looking at the important aspects of personality. The important aspects of someone's personality are the ones that going to affect how much emotion they experience, and those aspects are going to be ones that influence their social emotional interchanges. However, non-important personality traits may be related to important ones. For instance, although "Organized and hard working" is not an important factor, (how hard someone works is not going to play a large role in the emotional interchange when this person interacts) how serious that person is, which might be shown in how hard working they are, might play a role in a social interaction. For instance, there might be a violent clash between the personality of a serious person and a laid back person, generating a lot of emotion. So although two people might be equally hard working, maybe only one reflects this trait emotionally when they interact (or "radiates" it). There are only a few basic factors that generate large amounts of emotion when any two people interact:
- How serious (or mature) somone is could clash with how lazy (or immature) someone else is, causing either tension or an interesting interaction
- How cool or not people are or are perceived to be could cause a status conflict
- How physically appealing someone is could generate sexual interest or, if not sexual interest unconscious sexual interest that would be shown by how much someone likes someone else even though they might not be aware their interest is sexual in nature (that shows how this can function unconsciously)
- How old someone is could cause either identification and relation, or the opposite of that which might cause either tension or an interesting interaction
- How intelligent or dumb someone is could cause tension or relation (this also might vary depending on what the sitation is, becuase in certain situations different types of intellect are more valued)
- What someone's profession is would matter when interacting with that person in the context of their job (that shows how the context of the interaction (or what the interaction is even) also matters)
- How friendly or shy someone is could generate openness or seclusion in interaction


7.3.6C: The Life Cycle of HIV
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- Ying Liu
- City College of San Francisco
Learning Objectives
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Describe how the retrovirus HIV-1 accomplishes each of the following steps during its life cycle. (Include the following key words in your description: gp120, CD4, chemokine receptors, gp41, capsid, RNA genome, reverse transcriptase, double-stranded DNA intermediate, provirus, polyproteins, proteases, and budding.)
- viral attachment or adsorption to the host cell
- viral entry into the host cell
- viral movement to the site of replication within the host cell and production of a provirus.
- viral replication within the host cell
- viral assembly or maturation within the host cell and release from the host cell
- Name 3 types of cells HIV primarily infects and briefly explain why.
The Structure of the Human Immunodeficiency Virus (HIV)
HIV (see HIV A , HIV B and HIV C ) has an envelope derived from host cell membranes during replication. Associated with the envelope are two HIV-encoded glycoproteins, gp120 and gp41. Underneath the envelope is a protein matrix composed of p17. Inside the virus is a capsid or core made of the protein p24. The nucleocapsid also contains p6, p7, reverse transcriptase (p66/p51), integrase (p32), protease (p10), and 2 molecules of single-stranded RNA, the viral genome (see Figure \(\PageIndex{3}\)).
To view further electron micrographs of HIV, see the AIDS Pathology Tutorial at the University of Utah.
The Life Cycle for the Human Immunodeficiency Virus (HIV)
1. Attachment or Adsorption to the Host Cell
Initially, HIV uses a cellular protein called cyclophilin that is a component of its envelope to bind a low affinity host cell receptor called heparin. This first interaction (not shown in the illustrations or animations) enables the virus to initially make contact with the host cell. In order to infect a human cell, however, an envelope glycoprotein on the surface of HIV called gp120 must adsorbs to both a CD4 molecule and then a chemokine receptor found on the surface of only certain types of certain human cells.
Human cells possessing CD4 molecules include:
- T4-helper lymphocytes (also called T4-cells and CD4 + cells)
- monocytes
- macrophages
- dendritic cells
Chemokines are cytokines that promote an inflammatory response by pulling white blood cells out of the blood vessels and into the tissue to fight infection. Different white blood cells have receptors on their surface for different chemokines. The chemokine receptors are now thought to determine the type of CD4 + cell HIV is able to infect. First, a portion or domain of the HIV surface glycoprotein gp120 binds to its primary receptor, a CD4 molecule on the host cell. This induces a change in shape that enables the chemokine receptor binding domains of the gp120 to interact with a host cell chemokine receptor. The chemokine receptor functions as the viral co-receptor. This interaction brings about another conformational change that exposes a previously buried portion of the transmembrane glycoprotein gp41 called the fusion peptide that enables the viral envelope to fuse with the host cell membrane (see Figure \(\PageIndex{1}\)A , Figure \(\PageIndex{1}\)B) , and Figure \(\PageIndex{1}\)C) .
Animation: Adsorption of HIV to a T4-Helper Lymphocyte. The HIV envelope gp120 must attach to both a CD4 molecule and a chemokine receptor on the surface of such cells as macrophages and T4-helper lymphocytes in order to enter the cell. The gp120 first binds to a CD4 molecule on the plasma membrane of the host cell. The interaction between the gp120 and the CD4 molecule on the host cell induces a change in shape that brings the chemokine receptor binding domains of the gp120 into proximity with the host cell chemokine receptor
- Transmission electron micrograph showing envelope and glycoprotein spikes (gp120) of HIV ; courtesy of CDC.
- Scanning electron micrograph showing HIV infecting a T4-lymphocyte ; courtesy of CDC.
YouTube animation illustrating adsorption and penetration of HIV.
Most strains of HIV are referred to as M-tropic or T-tropic. The gp120 of M-tropic HIV (see Figure \(\PageIndex{2}\)) is able to adsorb to the CD4 molecules and the CCR5 chemokine receptors found on CD4 + macrophages, immature dendritic cells, and memory T4-lymphocytes. (M-tropic HIV are also called R5 viruses since they adsorb to the chemokine receptor CCR5.) M-tropic HIV require only low levels of CD4 molecules expressed on the surface of the host cell for infection. M-tropic HIV are thought to spread the infection. These strains appear to be slower-replicating and less virulent than the later T-tropic strains and do not cause the formation of syncytias. HIV initially replicates to high levels within macrophages without destroying them. (The T-tropic HIV, found later in HIV infection, are faster-replicating, more virulent, and lead to syncytia formation.)
As time goes by, mutation in the gene coding for gp120 enables some of the HIV to become dual tropic and able to infect both macrophages via the CCR5 chemokine receptor found on these cells, and T4-lymphocytes via the CCR5 and CXCR4 chemokine receptors found on these cells. (Duel-tropic HIV are also called R5X4 viruses since they adsorb to both the chemokine receptors CCR5 and CXCR4.)
Later during the course of HIV infection, most of the viruses have mutated their gp120 to become T- tropic (see Figure \(\PageIndex{2}\)) and infect primarily mature dendritic cells and T4-lymphocytes by way of CD4 and the CXCR4 co-receptors found on these cells. (T-tropic HIV are also called X4 viruses since they adsorb to the chemokine receptor CXCR4.) T-tropic HIV require high levels of CD4 molecules expressed on the surface of the host cell for infection. As mentioned, these T-tropic strains of HIV are faster-replicating and more virulent, and cause formation of syncytias and begin the cycles of T4-lymphocyte destruction.
HIV infecting microglia cells in the brain appear to bind to a CD4 molecule and a chemokine receptor called CCR3 found on these macrophage-like cells.
2. Viral Entry into the Host Cell
As mentioned above under adsorption, the binding of a portion or domain of the HIV surface glycoprotein gp120 to a CD4 molecule on the host cell induces a change in shape that brings the chemokine receptor binding domains of the gp120 into proximity with the host cell chemokine receptor. This, in turn, brings about a conformational change that exposes a previously buried portion of the transmembrane glycoprotein gp41 enabling the viral envelope to fuse with the host cell membrane (see Figure \(\PageIndex{5}\) and Figure \(\PageIndex{6}\)) . After fusion of the viral envelope with the host cell cytoplasmic membrane, the genome-containing protein core of the virus enters the host cell's cytoplasm. (Occasionally the virus enters by endocytosis, after which the viral envelope fuses with the endocytic vesicle releasing the genome-containing core into the cytoplasm.)
Animation: Penetration of HIV into Host Cell. The binding of a portion or domain of the HIV surface glycoprotein gp120 to a CD4 molecule on the host cell induces a change in shape that brings the chemokine receptor binding domains of the gp120 into proximity with the host cell chemokine receptor. This, in turn, brings about a conformational change that exposes a previously buried portion of the transmembrane glycoprotein gp41 enabling the viral envelope to fuse with the host cell membrane. After fusion of the viral envelope with the host cell cytoplasmic membrane, the genome-containing protein core of the virus enters the host cell's cytoplasm.
3. Viral Movement to the Site of Replication within the Host Cell and Production of a Provirus
During uncoating, the single-stranded RNA genomes within the core or capsid of the virus are released into the cytoplasm. HIV now uses the enzyme reverse transcriptase , associated with the viral RNA genome, to make a DNA copy of the RNA genome. (Normal transcription in nature is when the DNA genome is transcribed into mRNA which is then translated into protein. In HIV reverse transcription, RNA is reverse-transcribed into DNA.)
Reverse transcriptase has three enzyme activities:
- It has RNA-dependent DNA polymerase activity that copies the viral (+) RNA into a (-) viral complementary DNA (cDNA);
- It has ribonuclease activity that degrades the viral RNA during the synthesis of cDNA; and
- It has DNA-dependent DNA polymerase activity that copies the (-) cDNA strand into a (+) DNA to form a double-stranded DNA intermediate.
As the cDNA is being synthesized off of the RNA template the ribonuclease activity degrades the viral RNA genome (see Figure \(\PageIndex{7}\)A , Figure \(\PageIndex{7}\)B , and Figure \(\PageIndex{7}\)C) . The reverse transcriptase then makes a complementary DNA strand to form a double-stranded viral DNA intermediate (see Figure \(\PageIndex{7}\)D) .
Animation: HIV Copying RNA into DNA with Reverse Transcriptase. The single-stranded RNA genomes are released from the capsid. HIV uses the enzyme reverse transcriptase to transcribe its RNA genome into single-stranded DNA. As the DNA is being made, the RNA genome is degraded by an RNase. The reverse transcriptase then synthesizes a complementary DNA strand to produce a double-stranded DNA intermediate that enters the infected host cell's nucleus.
A viral enzyme called integrase then binds to the double-stranded viral DNA intermediate, transports it through the pores of the host cell's nuclear membrane, and inserts into one of the host cell's chromosomes to form a provirus (see Figure \(\PageIndex{8}\)A and Figure \(\PageIndex{8}\)B) .
Animation: Formation of a Provirus. An HIV enzyme called integrase is used to insert the HIV double-stranded DNA intermediate into the DNA of a host cell's chromosome. HIV is now a provirus.
After integration, the HIV proviral DNA can exist in either a latent or productive state, which is determined by genetic factors of the viral strain, the type of cell infected, and the production of specific host cell proteins.
The majority of the proviral DNA is integrated into the chromosomes of activated T4-lymphocytes. These generally comprise between 93% and 95% of infected cells and are productively infected, not latently infected. However, a small percentage of HIV-infected memory T4-lymphocytes persists in a resting state because of a latent provirus. These, along with infected monocytes, macrophages, and dendritic cells, provide stable reservoirs of HIV capable of escaping host defenses and antiretroviral chemotherapy.
4. Replication of HIV within the Host Cell
The vast majority of T4-lymphocytes, which are productively infected, immediately begin producing new viruses. In the case of the small percentage of infected, resting memory T4-lymphocytes, before replication can occur, the HIV provirus must become activated. This is accomplished by such means as antigenic stimulation of the infected T4-lymphocytes or their activation by factors such as cytokines, endotoxins, and superantigens.
Following activation of the provirus, molecules of (+) mRNA are transcribed off of the (-) proviral DNA strand by the enzyme RNA polymerase II. Once synthesized,HIV mRNA goes through the nuclear pores into the rough endoplasmic reticulum to the host cell's ribosomes where it is translated into HIV structural proteins, enzymes, glycoproteins, and regulatory proteins( see Figure \(\PageIndex{3}\) ).
A 9 kilobase mRNA is formed that is used for three viral functions:
a. Synthesis of Gag polyproteins (p55). These polyproteins will eventually be cleaved by HIV proteases to become HIV matrix proteins (MA; p17), capsid proteins (CA; p24), and nucleocapsid proteins (NC, p7). See Figure \(\PageIndex{9}\)A and Figure \(\PageIndex{9}\)B .
b. Synthesis of Gag-Pol polyproteins (p160). These polyproteins will eventually be cleaved by HIV proteases to become HIV matrix proteins (MA; p17), capsid proteins (CA; p24), proteinase molecules (protease or PR; p10), reverse transcriptase molecules (RT; p66/p51), and integrase molecules (IN; p32). See Figure \(\PageIndex{9}\)C and Figure \(\PageIndex{9}\)D .
c. During maturation, these RNA molecules also become the genomes of new HIV virions.
The 9kb mRNA can also be spliced to form a 4kb mRNA and a 2kb mRNA.
The 4kb mRNA is used to:
a. Synthesize the Env polyproteins (gp160). These polyproteins will eventually be cleaved by proteases to become HIV envelope glycoproteins gp120 and gp41. See Figure \(\PageIndex{9}\)E and Figure \(\PageIndex{9}\)F .
b. Synthesize 3 regulatory proteins called vif, vpr , and vpu .
The 2kb mRNA is used to synthesize 3 regulatory proteins known as tat, rev , and naf .
5. Viral Assembly or Maturation within the Host Cell and Release from the Host Cell
Assembly of HIV virions begins at the plasma membrane of the host cell. Maturation occurs either during the budding of the virion from the host cell or after its release from the cell.
- Transmission electron micrograph of HIV budding from a T4-lymphocyte ; courtesy of Dennis Kunkel's Microscopy .
Prior to budding, the Env polyprotein (gp160) goes through the endoplasmic reticulum and is transported to the Golgi complex where it is cleaved by a protease (proteinase) and processed into the two HIV envelope glycoproteins gp41 and gp120. These are transported to the plasma membrane of the host cell where gp41 anchors the gp120 to the membrane of the infected cell. See Figure \(\PageIndex{10}\)A , Figure \(\PageIndex{10}\)B , Figure \(\PageIndex{10}\)C , and Figure \(\PageIndex{10}\)D .
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GIF animation showing maturation of gp41 and gp120.
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The Gag (p55) and Gag-Pol (p160) polyproteins also associate with the inner surface of the plasma membrane along with the HIV genomic RNA as the forming virion begins to bud from the host cell.
During maturation, HIV proteases (proteinases) will cleave the remaining polyproteins into individual functional HIV proteins and enzymes such as matrix proteins (MA; p17), capsid proteins (CA; p24), reverse transcriptase molecules (RT; p66/p51), and integrase molecules (IN; p32).. See Figure \(\PageIndex{10}\)E, Figure \(\PageIndex{10}\)F, Figure \(\PageIndex{10}\)G, and Figure \(\PageIndex{10}\)H.
a. The Gag polyproteins (p55) will be cleaved by HIV proteases to become HIV matrix proteins (MA; p17), capsid proteins (CA; p24), and nucleocapsid proteins (NC, p7 and p6).
b. The Gag-Pol polyproteins (p160) will be cleaved by HIV proteases to become HIV matrix proteins (MA; p17), capsid proteins (CA; p24), proteinase molecules (protease or PR; p10), reverse transcriptase molecules (RT; p66/p51), and integrase molecules (IN; p32).
The various structural components then assemble to produce a mature HIV virion.
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GIF animation showing maturation of of HIV.
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6. Reinfection
Free viruses now infect new susceptible body cells. HIV can also be transmitted by cell-to-cell contact. This can occur when an infected cell with gp120 on its cytoplasmic membrane attaches to CD4 molecules and chemokine receptors on the surface of an uninfected cell. The cells then fuse (see Figure \(\PageIndex{11}\) and Figure \(\PageIndex{12}\)).
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Excellent Animation Summarizing the Life Cycle of HIV Courtesy of HHMI's Biointeractive. |
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YouTube Animation Illustrating Reproduction of HIV.
Courtesy of 3D Medical Animations Library, Dr. Rufus Rajadurai |
Exercise: Think-Pair-Share Questions
- State the role(s) of gp120 and gp41 in the life cycle of HIV.
- Why does HIV primarily infect T4-lymphocytes, macrophages, and dendritic cells?
- How do antiretroviral drugs that bind to HIV-encoded protease help to reduce the number of HIV in the body.
- If one could destroy all of the infected white blood cells in a person infected with HIV and then reconstitute the cells by giving a bone marrow transplant from a person homozygous for a deletion mutation in their gene coding for the chemokine receptor CCR5 (he or she can not make CCR5 molecules), describe how this might prevent HIV infection in the person receiving the transplant.
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Medscape article on infections associated with organisms mentioned in this Learning Object. Registration to access this website is free.
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Summary
- During adsorption, an envelope glycoprotein on the surface of HIV called gp120 must adsorbs to both a CD4 molecule and then a chemokine receptor found on the surface of only certain types of certain human cells such as T4-lymphocytes, monocytes, macrophages, and dendritic cells.
- Following adsorption, glycoprotein gp41 enabling the viral envelope to fuse with the host cell membrane, allowing the nucleocapsid of the virus enters the host cell's cytoplasm.
- During uncoating, the single-stranded RNA genomes within the capsid of the virus are released into the cytoplasm and HIV now uses the enzyme reverse transcriptase to make a single-stranded DNA copy of its single-stranded RNA genome. The reverse transcriptase then makes a complementary DNA strand to form a double-stranded viral DNA intermediate.
- A viral enzyme called integrase then binds to the double-stranded viral DNA intermediate, transports it through the pores of the host cell’s nuclear membrane, and inserts into one of the host cell's chromosomes to form a provirus.
- Following activation of the provirus, molecules of mostly polycistronic mRNA are transcribed off of the proviral DNA strand, go through the nuclear pores into the rough endoplasmic reticulum where it is translated by host cell's ribosomes HIV structural proteins, enzymes, glycoproteins, and regulatory proteins.
- Polyproteins translated from polycistronic mRNAs must be cleaved into function proteins by HIV protease enzymes.
- The two HIV envelope glycoproteins gp41 and gp120 are transported to the plasma membrane of the host cell where gp41 anchors the gp120 to the membrane of the infected cell. HIV obtains its envelope from the plasma membrane by budding.
- Most maturation occurs either during the budding of the virion from the host cell or after its release from the cell.
Questions
Study the material in this section and then write out the answers to these questions. Do not just click on the answers and write them out. This will not test your understanding of this tutorial.
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Describe how the retrovirus HIV-1 accomplishes each of the following steps during its life cycle. (Include the following key words in your description: gp120, CD4, chemokine receptors, gp41, capsid, RNA genome, reverse transcriptase, double-stranded DNA intermediate, provirus, polyproteins, proteases, and budding.)
- viral attachment or adsorption to the host cell (ans)
- viral entry into the host cell (ans)
- viral movement to the site of replication within the host cell and production of a provirus. (ans)
- viral replication within the host cell (ans)
- viral assembly or maturation within the host cell and release from the host cell (ans)
- Name 3 types of cells HIV primarily infects and briefly explain why. (ans)
- HIV possesses a genome of RNA. How then is HIV able to insert into the DNA of host cells and form a provirus? (ans)
- Multiple Choice (ans)


3.2: Electron Configurations According to Bohr and Pauli
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Skills to Develop
- Describe the Pauli Exclusion Principle
Many-electron Atoms
If there are multiple electrons, which orbits do they occupy? In atoms larger than hydrogen, the larger nuclear charge means that the orbits should be closer to the nucleus. If all the electrons are in the lowest energy orbit, even if repulsion expands the orbit a little, then the size of elements would get smaller as they get heavier. Also, it would get harder and harder to pull electrons off heavier elements, because they would be bound much more tightly to the more charged nuclei. Both of these are the opposite of the facts: sizes of elements increase a little as you go down the periodic table, and it is hardest to remove electrons from the lightest elements. Thus, it was clear that only some electrons could be in the lowest orbit.
Pauli was a theoretician "so good that experimental apparatus broke when he walked through the lab door."  He suggested that theory and data would fit well if each orbit (defined by 3 quantum numbers) could hold exactly 2 electrons. Thus as soon as each orbit was full, with 2, the next electron would have to go in the next higher orbit. Using this rule, Bohr and others determined the electron configurations (which electrons were in which state or orbit) of most of the elements, and found that the order matched the periodic table nicely! The movement to the next principal quantum number started a new period, so the theory fit all the data on valence and other properties.
Electron Spin
Pauli didn't know at the time why each orbital holds 2 electrons, but later it was found that a fourth quantum number was needed, because strong magnetic fields split the energy of the 2 electrons in one orbit into 2 different levels. (This is the basis of many important experimental techniques, especially NMR, used by chemists, and MRI, used in medical imaging.) A proposed explanation for this is that the electrons can "spin" in either direction, just like the earth spinning to give us day and night. This isn't exactly what happens, but the word spin is still used to describe this effect. The spin quantum number has values of +1/2 or −1/2. Thus, Pauli's idea is now called the Pauli Exclusion Principle, and it says that no 2 electrons in one atom can have exactly the same quantum numbers. Two electrons can occupy one orbit, but they must have opposite spins.
Electron Configurations
Bohr figured out the number of electrons in each shell , where a shell is all the electrons with the same principal quantum number. The pattern he used, which you can verify with the periodic table, was 2, 8, 8, 18, 18, 32, 32.
Based on Bohr's model, you can find the number of valence electrons or electrons in the highest shell by looking at the periodic table. (For now, let's not worry about transition metals, and lanthanoides.) Alkalis have 1 valence electron, because we have just started a new shell. Alkaline earths have 2, B has 3, C has 4, N has 5. Chalcogens have 6, halogens have 7, noble gases have 8. (You can see that this is kind of close to the valence we mentioned earlier.


10.4: Respiratory System Infections
The respiratory tract is one of the main portals of entry into the human body for microbial pathogens. On average, a human takes about 20,000 breaths each day. This roughly corresponds to 10,000 liters, or 10 cubic meters, of air. Suspended within this volume of air are millions of microbes of terrestrial, animal, and human origin—including many potential pathogens. A few of these pathogens will cause relatively mild infections like sore throats and colds. Others, however, are less benign. According to the World Health Organization, respiratory tract infections such as tuberculosis, influenza, and pneumonia were responsible for more than 4 million deaths worldwide in 2012. 1
At one time, it was thought that antimicrobial drugs and preventive vaccines might hold respiratory infections in check in the developed world, but recent developments suggest otherwise. The rise of multiple-antibiotic resistance in organisms like Mycobacterium tuberculosis has rendered many of our modern drugs ineffective. In addition, there has been a recent resurgence in diseases like whooping cough and measles, once-common childhood illnesses made rare by effective vaccines. Despite advances in medicine and public health programs, it is likely that respiratory pathogens will remain formidable adversaries for the foreseeable future.
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- 10.4.1: Anatomy and Normal Microbiota of the Respiratory Tract
- The upper respiratory tract is colonized by an extensive and diverse normal microbiota, many of which are potential pathogens. Few microbial inhabitants have been found in the lower respiratory tract, and these may be transients. Members of the normal microbiota may cause opportunistic infections, using a variety of strategies to overcome the innate nonspecific defenses (including the mucociliary escalator) and adaptive specific defenses of the respiratory system.
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- 10.4.2: Bacterial Infections of the Respiratory Tract
- The respiratory tract can be infected by a variety of bacteria, both gram positive and gram negative. Although the diseases that they cause may range from mild to severe, in most cases, the microbes remain localized within the respiratory system. Fortunately, most of these infections also respond well to antibiotic therapy.
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- 10.4.3: Viral Infections of the Respiratory Tract
- Viruses cause respiratory tract infections more frequently than bacteria, and most viral infections lead to mild symptoms. The common cold can be caused by more than 200 viruses, typically rhinoviruses, coronaviruses, and adenoviruses, transmitted by direct contact, aerosols, or environmental surfaces. Due to its ability to rapidly mutate through antigenic drift and antigenic shift, influenza remains an important threat to human health. Two new influenza vaccines are developed annually.
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- 10.4.4: Respiratory Mycoses
- Fungal pathogens are ubiquitous in the environment. Serological studies have demonstrated that most people have been exposed to fungal respiratory pathogens during their lives. Yet symptomatic infections by these microbes are rare in healthy individuals. This demonstrates the efficacy of the defenses of our respiratory system. In this section, we will examine some of the fungi that can cause respiratory infections.
Footnotes
- 1 World Health Organization. “The Top Ten Causes of Death.” May 2014. http://www.who.int/mediacentre/factsheets/fs310/en/
Thumbnail: Coronaviruses are a group of viruses known for causing the common cold. They have a halo or crown-like (corona) appearance when viewed under an electron microscope. (Public Domain; CDC/Dr. Fred Murphy).


15.0: Introduction
Substance use disorders are a major public health concern in the United States and affect millions of people around the world. The consequences of substance use disorders can be catastrophic for the client, their family, and society at large. As frontline health care providers, nurses play a crucial role in the prevention, identification, and treatment of clients with substance use disorders. This chapter will review the definition of substance use disorders, how to identify clients with substance use disorders, and how to manage their condition. In addition to nonpharmacologic treatment options for substance use disorders, this chapter will also review medication therapy to assist in the treatment of opioid, alcohol, and nicotine use disorders.


1.3.11: Summary
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Key Terms
- Charisma
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A special personal magnetic charm or appeal that arouses loyalty and enthusiasm in a leaderfollower relationship.
- Charismatic leader
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A person who possesses legitimate power that arises from “exceptional sanctity, heroism, or exemplary character.”
- Consideraion
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A “relationship-oriented” leader behavior that is supportive, friendly, and focused on personal needs and interpersonal relationships.
- Contingency theory of leadership
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A theory advanced by Dr. Fred E. Fiedler that suggests that different leadership styles are effective as a function of the favorableness of the leadership situation least preferred.
- Designated leader
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The person placed in the leadership position by forces outside the group.
- Emergent leader
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The person who becomes a group’s leader by virtue of processes and dynamics internal to the group.
- Formal leader
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That individual who is recognized by those outside the group as the official leader of the group.
- Great man theory of leadership
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The belief that some people are born to be leaders and others are not.
- Informal leader
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That individual whom members of the group acknowledge as their leader.
- Initiating structure
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A “task-oriented” leader behavior that is focused on goal attainment, organizing and scheduling work, solving problems, and maintaining work processes.
- Leadership
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A social (interpersonal) influence relationship between two or more persons who depend on each other to attain certain mutual goals in a group situation.
- Least-preferred coworker (LPC)
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The person with whom the leader least likes to work.
- Path-goal theory of leadership
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A theory that posits that leadership is path- and goal-oriented, suggesting that different leadership styles are effective as a function of the task confronting the group.
- Transformational leader
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A leader who moves and changes things “in a big way” by inspiring others to perform the extraordinary.
- Visionary leader
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A leader who influences others through an emotional and/or intellectual attraction to the leader’s dreams of what “can be.”
Summary of Learning Outcomes
13.2 The Nature of Leadership
1. What is the nature of leadership and the leadership process?
Leadership is a primary vehicle for fulfilling the directing function of management. Because of its importance, theorists, researchers, and practitioners have devoted a tremendous amount of attention and energy to unlocking the secrets of effective leadership. They have kept at this search for perhaps a greater period of time than for any other single issue related to management.
13.3 The Leadership Process
2. What are the processes associated with people coming to leadership positions?
Organizations typically have both formal and informal leaders. Their leadership is effective for virtually identical reasons. Leadership and management are not the same. Although effective leadership is a necessary part of effective management, the overall management role is much larger than leadership alone. Managers plan, organize, direct, and control. As leaders, they are engaged primarily in the directing function.
13.4 Types of Leaders and Leader Emergence
3. How do leaders influence and move their followers to action?
There are many diverse perspectives on leadership. Some managers treat leadership primarily as an exercise of power. Others believe that a particular belief and attitude structure makes for effective leaders. Still others believe it is possible to identify a collection of leader traits that produces a leader who should be universally effective in any leadership situation. Even today, many believe that a profile of behaviors can universally guarantee successful leadership. Unfortunately, such simple solutions fall short of the reality.
13.5 The Trait Approach to Leadership
4. What are the trait perspectives on leadership?
13.6 Behavioral Approaches to Leadership
5. What are the behavioral perspectives on leadership?
It is clear that effective leaders are endowed with the “right stuff,” yet this “stuff” is only a precondition to effective leadership. Leaders need to connect with their followers and bring the right configuration of knowledge, skills, ability, vision, and strategy to the situational demands confronting the group.
13.7 Situational (Contingency) Approaches to Leadership
6. What are the situational perspectives on leadership?
We now know that there is no one best way to be an effective leader in all circumstances. Leaders need to recognize that how they choose to lead will affect the nature of their followers’ compliance with their influence tactics, and ultimately impacts motivation, satisfaction, performance, and group effectiveness. In addition, the nature of the situation—contextual demands and characteristics of the follower—dictates the type of leadership that is likely to be effective. Fiedler focuses on leader traits and argues that the favorableness of the leadership situation dictates the type of leadership approach needed. He recommends selecting leaders to match the situation or changing the situation to match the leader. Path-goal theory focuses on leader behavior that can be adapted to the demands of a particular work environment and organizational members’ characteristics. Path-goal theorists believe both that leaders can be matched with the situation and that the situation can be changed to match leaders. Together, these theories make clear that leadership is effective when the characteristics and behavior of the leader match the demands of the situation.
13.8 Substitutes for and Neutralizers of Leadership
7. What does the concept of “substitute for leadership” mean?
Characteristics of followers, tasks, and organizations can substitute for or neutralize many leader behaviors. Leaders must remain aware of these factors, no matter which perspective on leadership they adopt. Such awareness allows managers to use substitutes for, and neutralizers of, leadership to their benefit, rather than be stymied by their presence.
13.9 Transformational, Visionary, and Charismatic Leadership
8. What are the characteristics of transactional, transformational, and charismatic leadership?
In recent years, there has been a renewed interest in key leader traits and behaviors. As organizations face increasing amounts of chaos in their external environments, searches for “the right leader” who can bring about major organizational transformations has intensified. This search once again focuses our attention on a set of “key” motives, knowledge, skills, and personality attributes. Emerging from this search has been the identification of the charismatic and transformational leader.
13.10 Leadership Needs in the 21st Century
9. How do different approaches and styles of leadership impact what is needed now?
Leadership in the high-involvement organization differs dramatically from that in the traditional and control-oriented organization. Leaders external to the team have as one of their primary roles empowering group members and the teams themselves to self-lead and self-manage. Leaders internal to the team are peers; they work alongside and simultaneously facilitate planning, organizing, directing, controlling, and the execution of the team’s work.
Although we know a great deal about the determinants of effective leadership, we have much to learn. Each theory presented in this chapter is put into practice by managers every day. None provides the complete answer to what makes leaders effective, but each has something important to offer.
Finally, our understanding of leadership has many shortcomings and limitations. The existing literature is largely based on observations from a Western industrialized context. The extent to which our theories of leadership are bound by our culture, limiting generalization to other cultures, is largely unknown. Cross-cultural leadership research will no doubt intensify as the global economy becomes an ever more dominant force in the world
Chapter Review Questions
- Define leadership and distinguish between leadership and management.
- Discuss the processes associated with people coming to positions of leadership.
- Discuss the different forms of power available to leaders and the effects associated with each.
- It has been observed that effective leaders have the “right stuff.” What traits are commonly associated with leader emergence and effective leaders?
- Both the Ohio State University and University of Michigan leadership studies identified central leader behaviors. What are these behaviors, and how are they different from one another?
- Blake and Mouton’s work with the Leadership Grid® identified several leadership types. What are they, and how does this leadership model look from the perspective of situation theories of leadership?
- Identify and describe the three situational variables presented in Fiedler’s contingency theory of leadership.
- What are the four leadership behaviors in the path-goal theory of leadership?
- Discuss the differences between the internal and external leadership roles surrounding self-managed work teams.
- What are substitutes for leadership? What are neutralizers? Give an example of each.
- What are the distinguishing features of the transformational and the charismatic leader?
Management Skills Application Exercises
- Identify a charismatic leader and a leader with little charisma. What are the traits and skills that allow them to succeed in their roles? How can you incorporate the traits that allow them to be successful in their roles into the skills you will need to have in a leadership position?
- You have just taken a leadership position where 40 percent of the workforce telecommutes. You want to encourage teamwork and want to ensure that telecommuting is not hurting teamwork. What is your plan to discover how things are working and how to communicate your desire to have effective teamwork?
- You are at a meeting, and during the meeting someone on the team addresses their manager and points out a crucial mistake that could doom the project. The person says that their manager should have caught it and because of that should resign. As a leader of the group, how would you deal with the subordinate, the manager, and communication with the entire team?
Managerial Decision Exercises
- You are the newly appointed commissioner of a major sports league that is currently in a very public game three of a best-of-seven-game playoff. After an emotional opening ceremony that recognizes a tragic event in the community that is widely praised, you settle in to enjoy the game. Early in the game, a player on one team is seen celebrating a scoring play by acting out a racially insensitive behavior after the play. How would you act in a leadership position? Read the ESPN article [ http://www.espn.com/mlb/ story/_/id/21199462/rob-manfred-leadership-was-tested-yuli-gurriel-racially-insensitive-behaviorpassed] and comment on how this commissioner acted in this instance.
- One of the challenges for a new manager in a leadership position is managing stress. Reflect on a time in your life where you have taken a leadership role in a summer job, as a member of a team, or in a study group for this or another course. Develop a stress management plan that includes how you can recognize stress, how you will notice the stress, how you will manage changes to address stress, and how you will seek outside counsel and help, including a mentor to help you manage stress.
- Few people would want to hire a skilled manager with no leadership skills, and you would not want to hire an inspirational leader who can't manage planning, delegating, or keeping things organized. Draw two "T accounts" with positive attributes on the left and negative attributes on the right for managerial skills and leadership skills that you would look for as a hiring manager for a crucial managerial and leadership position in your organization.
Exhibit 13.13 (Attribution: Copyright Rice University, OpenStax, under CC-BY 4.0 license)
Critical Thinking Case
The Leadership Challenge at United
Anyone who has traveled even a little has at least one airline horror story: being stranded at an airport, obnoxious passengers, missed connections, flight delays, or just bad in-flight food. Even the most seasoned travelers would be hard-pressed to match Dr. David Dao’s experience of being forcibly removed, kicking and screaming, from a United Airlines flight. Most airline horror stories don’t end in a concussion, missing teeth, and a broken nose.
United Airlines CEO Oscar Munoz’s strangely detached response only made things worse. The incident was caught on video, and that video went viral almost immediately. Munoz issued a response that mischaracterized what plainly happened in the video and termed the violent assault as a passenger "reaccommodation" (Taylor 2017). Social media erupted with condemnation, which was echoed by late-night monologues. United was left with a damaged reputation, and its management was left wondering why their processes failed, what to do to mitigate the damage, and how to both restore their reputation and ensure that company values are followed in the future.
William Taylor (2017), in a commentary inFortune, attributes United’s “re-accommodation” disaster as the product of company policy, airport security procedures, pilot protocols, and the “wisdom of crowds.” At each step, the gate agent, pilot, airport security, and the passengers themselves could have intervened but didn’t.
Brian Fielkow, business leader, author, and keynote speaker, writing at Entrepreneur.com, outlined some points that apply to Munoz’s response and the first reactions by United. Citing United’s core values, Fielkow points to Munoz’s failure to address the incident in light of the company’s values, take the blame, or even accurately describe what happened on the plane. Any oneof these lapses in leadership would have caused confusion or stymied the recovery process. As a leader, Munoz was setting the tone for thousands of people. Seemingly abandoning United’s core values likely caused a rift in trust or just simple confusion company-wide. Miscasting the situation in a world of smartphones and social media reach only multiplied the effect. As a leader, Munoz was duty-bound to take responsibility for what literally the entire world saw—a breach of social ethics, let alone United’s core values. Failing to do this immediately created a problem larger than poorly planned company policy or just a perfect storm of contributing outside factors. Fielkow is keen to point out another crucial part of a company response— “You can’t walk it back” (2017 n.p.). Before responding, leadership should take time to gather the facts and thoroughly consider the possibilities of how the message will be received. Again, Munoz’s response failed at several key points, leading to the perception that Munoz’s second statement was “an attempt at damage control” (Fielkow 2017 n.p.).
Al Bolea, a leadership trainer, also attributes the incident to leadership failure. In a piece written for Applied Leadership , Bolea writes, “It’s about front line employees getting the wrong messages from the most senior levels of the company.” He contends that the mindset within United put procedures above context in the minds of the employees. What the gate agents should have considered was the company’s reputation, which should have prevented them from doing something most airline customers see as “profoundly immoral” (Bolea 2017 n.p.)
William C. Taylor, cofounder of Fast Company, also criticized the lack of leadership across United. As the presumptive leader of the flight, shouldn’t the pilot have done something? Why didn’t the gate agent think outside the box to solve the problem of getting the crew members from Chicago to Louisville, Kentucky? Why didn’t—or couldn’t—the gate agent use what Taylor refers to as a “common sense and a little bit of creativity” and prevent a highly embarrassing (and ultimately expensive) fiasco? Taylor muses that he would like to think he would have done more than shoot video, but the passengers on the flight remained quiet and submissive, expressing no group outrage. Finally, Taylor questions the weak initial response from United’s CEO, Oscar Munoz, writing, “If CEO Oscar Munoz’s goal was to make a disastrous situation even worse, well, he gets credit as a leader for succeeding at that” (2017 n.p.). And of the board, he questions their response, and says that response will be a “make or break test” of the company’s character (Taylor 2017).
So what will it take to lead United out of such a public mistake?
According to Brian Fielkow, the incident flew in the face of United’s core values, values which should never be sacrificed. United should have acknowledged this and addressed that failure. United should have held itself accountable for the incident rather than try to deflect blame. Fielkow contends that Munoz’s first response was to blame the passenger when Munoz should have accepted responsibility instead. Further, Fielkow writes that companies should anticipate what “can” go wrong, something the gate agents at United failed to do. Increasing passenger compensation to even three times the normal ticket price would have been cheaper than the PR nightmare (and stock price drop) that followed. After Munoz’s tepid response failed to quell general complaints about United’s handling of the passenger, he tried to issue a second “more appropriate” statement, but by then the damage had been done. Fielkow recommends waiting before issuing a response if need be. It’s better to prepared and issue a suitable response than to try to walk back a bad response. Above all, Fielkow recommends leaders “be human.” The first response Munoz gave had little empathy and made him, and United, appear insensitive and callous. A company’s first response should be to empathize with the customer, even if the customer is wrong. He writes, “When triaging a difficult problem, above all recognize the human factor” (Fielkow 2017 n.p.).
Writing in Forbes , Glenn Llopis emphasizes that how managers react to failure shapes their futures as leaders. Not only how leaders respond, but what is learned from a failure, will affect how future decisions are approached. Remember, you have to be doing something to fail, and if you never fail, then you aren’t stretching yourself. Venturing into the unknown and unfamiliar always risks failure (Llopis 2012).
Sources:
Fielkow, Brian. 2017. “5 Leadership Failures that Contributed to the United Fiasco.” Entrepreneur. https://www.entrepreneur.com/article/292820
Bolea, Al. 2017. “United Airlines: A System Failure?”Applied Leadership.http://appliedleadership.co/leadership/ united-airlines-system-failure/
Taylor, William C. 2017. “Where was the Pilot on That United Airlines Flight?” Fortune.http://fortune.com/2017/ 04/11/united-airlines-video/
Llopis, Glenn. 2012. “5 Things Failure Teaches You About Leadership.”Forbes.https://www.forbes.com/sites/ glennllopis/2012/08/20/5-things-failure-teaches-you-about-leadership/2/#2f44c3873e70
Questions:
- How have other airlines handled similar situations?
- How much was in United Airlines’s control, and how much was actually outside their control? What social or company factors caused a seemingly common practice to escalate to this level?
- How did the other airlines or the industry respond to the United Airlines incident?


4.2: Classes of Filters
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There are four main classes of filters used in EEG/ERP research. They’re typically named in terms of the frequencies that they pass, not the frequencies that are filtered out (much as an air filter passes air and filters out dust).
I don’t ordinarily recommend applying notch filters (unless they are necessary during the recording process); it’s usually better to use a low-pass filter that attenuates all the high frequencies. However, if you don’t want to use a low-pass filter with a cutoff of 20 or 30 Hz (e.g., because you are interested in relatively high-frequency activity), a very sophisticated line noise filtering approach (Mitra & Pesaran, 1999) is available in EEGLAB as the cleanline plugin (see Bigdely-Shamlo et al., 2015 for important details about implementing this tool). Another tool called Zapline is can also be used for this purpose (de Cheveigné, 2020; Klug & Kloosterman, 2022), but it is newer and hasn't yet accumulated a strong track record.


7.3: Intradermal and Subcutaneous Injections
Intradermal injections (ID) are injections administered into the dermis, just below the epidermis. The ID injection route has the longest absorption time of all parenteral routes. These types of injections are used for sensitivity tests, such as TB (see Figure 7.13), allergy, and local anesthesia tests. The advantage of these tests is that the body reaction is easy to visualize, and the degree of reaction can be assessed. The most common sites used are the inner surface of the forearm and the upper back, under the scapula. Choose an injection site that is free from lesions, rashes, moles, or scars, which may alter the visual inspection of the test results (Lynn, 2011).
Equipment used for ID injections is a tuberculin syringe calibrated in tenths and hundredths of a millilitre, and a 1/4 to 1/2 in., 26 or 27 gauge needle. The dosage of an ID injection is usually under 0.5 ml. The angle of administration for an ID injection is 5 to 15 degrees. Once the ID injection is completed, a bleb (small blister) should appear under the skin. Checklist 56 outlines the steps to administer an intradermal injection.
Checklist 56: Administering an Intradermal (ID) InjectionDisclaimer: Always review and follow your hospital policy regarding this specific skill. |
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Safety Considerations:
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Steps |
Additional Information |
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| 1. Prepare medication or solution as per agency policy. Ensure all medication is properly identified. Check physician orders, Parenteral Drug Therapy Manual (PDTM), and MAR to validate medication order and guidelines for administration. |
Properly identifying medication decreases risk of inadvertently administering the wrong medication.
Preparing medications ensures patient safety with medication administration. |
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| 2. Perform hand hygiene; gather supplies. | Gather all supplies: medication syringe, non-sterile gloves, alcohol swab and sterile gauze, Band-Aid (if required). | |||
| 3. Enter room and introduce yourself, explain procedure and the medication, and allow patient time to ask questions. | Explaining rationale increases the patient’s knowledge and reduces their anxiety. | |||
| 4. Close the door or pull the bedside curtains. | This provides patient privacy. | |||
| 5. Compare MAR to patient wristband and verify this is the correct patient using two identifiers. |
This ensures accuracy of the medication or solution and prevents errors.
Two patient identifiers are patient name and date of birth. |
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| 6. Assess patient for any contraindications to the medications. | Assessment is a prerequisite for every medication given. | |||
| 7. Select appropriate site for administration. Assist the patient to the appropriate position as required. | Site should be free from lesions, rashes, and moles. Selecting the correct site allows for accurate reading of the test site at the appropriate time. | |||
| 8. Perform hand hygiene and apply non-sterile gloves. | Gloves help prevent exposure to contaminants. | |||
| 9. Clean the site with an alcohol swab or antiseptic swab. Use a firm, circular motion. Allow the site to dry. | Pathogens from the skin can be forced into the tissues by the needle. Allowing the skin to dry prevents introducing alcohol into the tissue, which can be irritating and uncomfortable. | |||
| 10. Remove needle from cap by pulling it off in a straight motion. | This decreases risk of accidental needle-stick injury. | |||
| 11. Using non-dominant hand, spread the skin taut over the injection site. | Taut skin provides easy entrance for the needle. | |||
| 12. Hold the syringe in the dominant hand between the thumb and forefinger, with the bevel of the needle up. | This allows for easy handling of the syringe. | |||
| 13. Hold syringe at a 5- to 15-degree angle from the site. Place the needle almost flat against the patient’s skin, bevel side up, and insert needle into the skin. Insert the needle only about 1/4 in., with the entire bevel under the skin. | Keeping the bevel side up allows for smooth piercing of the skin and induction of the medication into the dermis. | |||
| 14. Once syringe is in place, slowly inject the solution while watching for a small weal or bleb to appear. | The presence of the weal or bleb indicates that the medication is in the dermis. | |||
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15. Withdraw the needle at the same angle as insertion, engage safety shield or needle guard, and discard in a sharps container.
Do not massage area after injection. |
Withdrawing at the same angle as insertion minimizes discomfort to the patient and damage to the tissue.
Proper needle disposal prevents needle-stick injuries. Massaging the area may spread the solution to the underlying subcutaneous tissue. Gently pat with sterile gauze if blood is present. |
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| 16. If injection is a TB skin test, circle the area around the injection site to allow for easy identification of site in three days. | ||||
| 17. Discard remaining supplies, remove gloves, and perform hand hygiene. | This prevents the spread of microorganisms. | |||
| 18. Document the procedure and findings according to agency policy. | Proper documentation helps ensure patient safety. Document time, date, location, and type of medication injected. | |||
| 19. Evaluate the patient response to injection within appropriate time frame. | The patient will need to be evaluated for therapeutic and adverse effects of the medication or solution. | |||
| Data source: ATI, 2015a; Berman & Snyder, 2016; Brookside Associates, 2015a; Clayton, Stock, & Cooper, 2010; Perry et al., 2014 |
Subcutaneous Injections
Subcutaneous (SC) injections are administered into the adipose tissue layer just below the epidermis and dermis. This tissue has few blood vessels, so drugs administered by this route have a slow, sustained rate of absorption. Sites for SC injections include the outer aspect of the upper arm, the abdomen (from below the costal margin to the iliac crest) within one inch of the belly button, anterior aspects of the thighs, upper back, and upper ventral gluteal area (Lynn, 2011) (see Figure 7.14).
Choose a site that is free of skin lesions and bony prominences. Site rotation prevents the formation of lipohypertrophy or lipoatrophy in the skin. Physical exercise or application of hot or cold compresses influences the rate of drug absorption by altering local blood flow to the tissues. Any condition that impairs that blood flow to the subcutaneous tissue contradicts the use of subcutaneous injections. Examples of subcutaneous medications include insulin, opioids, heparin, epinephrine, and allergy medication (Perry et al., 2014).
To administer an SC injection, a 25 to 30 gauge, 3/8 in. to 5/8 in. needle is used. Some subcutaneous injections come prefilled with the syringe attached. Always confirm that the right-size needle is appropriate for the patient before use. Subcutaneous injections are usually given at a 45- to 90-degree angle. The angle is based on the amount of subcutaneous tissue present. Generally, give shorter needles at a 90-degree angle and longer needles at a 45-degree angle (Lynn, 2011). SC injections do not need to be aspirated as the likelihood of injecting into a blood vessel is small. Usually, no more than 1 ml of medication is given subcutaneously, as larger amounts may cause discomfort to the patient and may not be absorbed appropriately (Lynn, 2011).
There are varying opinions on whether to pinch the skin during administration. Pinching is advised for thinner patients in order to lift the adipose tissue up and away from the underlying muscle and tissue. If pinching is used, release the pinch when the needle is inserted to avoid injecting into compressed tissue. Note, too, that elevating or pinching the skin has been found to increase the risk of injury, as the needle may pierce the opposite side of the skin fold and enter the skin of the health care worker (Black, 2013). The abdomen is the best location for an SC injection if a patient has little peripheral SC tissue. If patient is obese, use a needle that is long enough to insert through the tissue at the base of the skin fold (Perry et al., 2014).
Insulin SC Injections
Insulin is considered a high-risk medication, and special care must be taken to ensure the correct amount of medication and type of insulin is administered at the correct time. As well, safety checks related to a patient receiving SC insulin should be carried out (Ellis & Parush, 2012). Table 7.5 lists specific guidelines for administering insulin (and see Figure 7.15).
| Table 7.5 Guidelines for Administering SC Insulin | |||
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Insulin |
Additional Information |
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| Insulin is considered a high-risk medication. | Special care must be taken to ensure the correct amount of medication and type of insulin is administered, at the correct time. It is highly recommended to always get your insulin dosages double-checked by another health care provider. Always follow the standard for medication preparation at your agency. | ||
| Insulin is only administered using an insulin syringe. | Insulin is the only drug with its own type of syringe with a needle attached. Insulin is always ordered and administered in units, based on a blood sugar reading and a diabetic insulin protocol (or sliding scale). Some hospitals have preprinted physician orders, and some hospitals have handwritten orders. Insulin syringes can come in 30-, 50-, or 100-unit measurements. Always read the increments (calibration) carefully. | ||
| There are different types of insulin. | There are rapid-, short-, intermediate-, and long-acting insulins. For each type of insulin, it is important to know how the insulin works and the onset, peak, and duration of the insulin. | ||
| Administering two different types of Insulin. |
If a patient is ordered two types of insulin, some insulins may be mixed together in one syringe. Many insulins MAY NOT be mixed together. Do not mix Lantus (Glargine) or Levemir (Determir).If administering cloudy insulin preparations (Humulin – N), gently roll the vial between the palms of your hands to re-suspend the medication.
Always draw up the short acting insulin first, to prevent it from being contaminated with the long acting. If too much insulin is drawn up from the second vial, discard syringe and start again. Always check with the PDTM for the most current guidelines regarding insulin administration.Insulin orders may change from day to day. Always ensure the most current physician orders are being followed. |
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| Know about rotating injection sites. | Injection site rotation is no longer necessary as newer insulins have a lower risk for hypertrophy of the skin. Typically, a patient will pick one anatomic area (e.g., upper arm) and rotate the injection sites within that region to maintain consistent insulin absorption from day to day. Insulin absorption rates vary from site to site. The abdomen absorbs the fastest, followed by the arms, thighs, and buttocks. | ||
| Know when to administer insulin. | The timing of insulin injections is critical to correct insulin administration based on blood sugar levels and when the patient will eat. Knowing the peak action and duration of insulin is critical to proper insulin medication management. If giving insulin, always ensure the patient is not nauseated, is able to eat, and that food is arriving before the insulin starts working. Typically, short- or rapid-acting insulin is given 15 minutes before meals. Intermediate- or long-acting insulin may be given twice daily, at breakfast and dinner. | ||
| Measure blood sugar levels and food intake. | Insulin injections are based on blood sugar values and on when the patient will eat. The timing of an insulin injection is critical to ensure the patient receives insulin correctly. | ||
| Use insulin injection pens. |
Injection pens
are a new technology used by patients to self-inject insulin using a syringe, needle, and prefilled cartridge of insulin. It is essential that patients be taught how to use injection pens so they understand the technology.
A mini-infusion pump is a battery-operated machine that delivers medications in very small amounts to patients with controlled infusion times. The most common types of mini-infusion sets are insulin pumps or subcutaneous infusion devices. For more information on mini-infusion sets and volume-controlled sets, see Suggested Online Resources in section 7.8. |
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| Data source: Canadian Diabetes Association, 2013; Perry et al., 2014 |
Special considerations:
- Insulin is stored in the refrigerator. When a vial is in use, it should be at room temperature. Do not administer cold insulin. Check agency policy for how long a vial can be used.
- Patients who take insulin should monitor their blood sugar (glucose) levels as prescribed by their health care provider.
- Vials of insulin should be inspected prior to use. Any change in appearance may indicate a change in potency.
- Use the type of insulin prescribed. Do not change the type unless ordered by a health care provider.
- Allow patient to choose site for injection. A patient may self-administer insulin if it’s determined to be safe and in the patient’s best interest.
- All health care providers should be aware of the signs and symptoms of hypoglycemia. Signs and symptoms include fruity breath, restlessness, agitation, confusion, slurring of words, clammy skin, inability to concentrate or follow commands, hunger, and nausea. The patient may complain of blurred or double vision. Late signs include unconsciousness. Hypoglycemia is a medical emergency. Always have an emergency diabetic kit available. If a conscious diabetic patient appears to be hypoglycemic or has a blood sugar (glucose) reading of 4 mmol/L or lower, give glucose, such as sucrose tablets, solution, or juice. Follow agency policy regarding hypoglycemic reactions.
Heparin SC Injections
Heparin is an anticoagulant used to reduce the risk of thrombosis formation by suppressing clot formation (Perry et al., 2014). Heparin is also considered a high-alert medication (ISMP, 2014).
Table 7.6 provides specific guidelines to consider before and after administering heparin.
| Table 7.6 Guidelines for Administering SC Heparin | |||
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Heparin |
Additional Information |
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| Heparin is considered a high-risk medication. | Heparin is available in vials and prefilled syringes in a variety of concentrations. Because of the dangerous adverse effects of the medication, it is considered a high-risk medication. Always follow agency policy regarding the preparation and administration of heparin. | ||
| Rotate heparin injection sites. | It is important to rotate heparin sites to avoid bruising in one location. To minimize bruising and pain associated with heparin injections, they can be given in the abdominal area, at least 5 cm away from the belly button. | ||
| Know the risks associated with heparin. | There are many risks associated with the administration of heparin, including bleeding, hematuria, hematemesis, bleeding gums, and melena. | ||
| Review lab values. | Review lab values (PTT and aPTT) before and after heparin administration. | ||
| Use prepackaged heparin syringes. | Many agencies use prepackaged heparin syringes. Always follow the standards for safe medication administration when using prefilled syringes. Low molecular weight heparin (LMWH) is more effective in some patients. | ||
| Assess patient conditions prior to administration. | Some conditions increase the risk for hemorrhage (bleeding), such as recent childbirth, severe diabetes, severe kidney and liver disease, severe traumas, cerebral or aortic aneurysm, cerebral vascular accidents (CVA), blood dyscrasias, and severe hypotension. | ||
| Assess medications prior to administration. | Over-the-counter (OTC) herbal medications, such as garlic, ginger, and horse chestnut, may interact with heparin. Additional medications that may interact include Aspirin, NSAIDS, cephalosporins, anti-thyroid agents, thrombolytics, and probenecids. | ||
| Data source: Clayton et al., 2010; Ogston-Tuck, 2014b; Perry et al., 2014 |
Checklist 57 provides the steps to complete a subcutaneous injection.
Checklist 57: Administering a Subcutaneous InjectionsDisclaimer: Always review and follow your hospital policy regarding this specific skill. |
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Safety Considerations:
|
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Steps |
Additional Information |
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| 1. Prepare medication or solution as per agency policy. Always compare the physician orders with the MAR. | Preparing medications ensures patient safety with medication administration. | ||
| 2. Perform hand hygiene; gather supplies. | You will need medication syringe, non-sterile gloves, alcohol swab and sterile gauze, Band-Aid. | ||
| 3. Enter room and introduce yourself. Identify patient using two acceptable identifiers, explain procedure and the medication, and allow patient time to ask questions. | Explaining rationale increases the patient’s knowledge and reduces their anxiety. | ||
| 4. Close the door or pull the bedside curtains. | This provides patient privacy. | ||
| 5. Compare MAR to patient wristband and verify this is the correct patient using two identifiers. | This ensures accuracy of the medication or solution and prevents errors. | ||
| 6. Assess patient for any contraindications for the medications. | Assessment is a prerequisite to the administration of medications. | ||
| 7. Put on non-sterile gloves. | Gloves help prevent exposure to contaminants. | ||
| 8. Select appropriate site for administration. Assist the patient to the appropriate position as required. | Site should be free from lesions, rashes, and moles. Choosing the correct site allows for accurate reading of the test site at the appropriate time. | ||
| 9. Clean the site with an alcohol swab or antiseptic swab. Use a firm, circular motion. Allow the site to dry. | Pathogens from the skin can be forced into the tissues by the needle. Allowing the skin to dry prevents introducing alcohol into the tissue, which can be irritating and uncomfortable. | ||
| 10. Remove the needle cap with the non-dominant hand, pulling it straight off. | This technique lessens the risk of an accidental needle-stick injury. | ||
| 11. Grasp or pinch the area surrounding the injection site, or spread the skin taut at the site. | The decision to create a skin fold is based on the nurse’s assessment of the patient and the needle length used. Pinching is advised for thinner patients. | ||
| 12. Hold the syringe in the dominant hand between the thumb and forefinger. Insert the needle quickly at a 45- to 90-degree angle. | Inserting quickly causes less pain to the patient. Subcutaneous tissue is abundant in well-nourished, well-hydrated people. For patients with little subcutaneous tissue, it is best to insert the needle at a 45-degree angle. | ||
| 13. After the needle is in place, release the tissue. Move your non-dominant hand to steady and lower the end of the needle. With your dominant hand, inject the medication at a rate of 10 seconds per ml. Avoid moving the syringe. | Keeping the needle steady helps keep the needle in place. | ||
| 14. Withdraw the needle quickly at the same angle at which it was inserted, while supporting the surrounding tissue with your non-dominant hand. | Withdrawing at the same angle prevents tissue damage and increased pain at the injection site. | ||
| 15. Using a sterile gauze, apply gentle pressure at the site after the needle is withdrawn. Do not massage the site. | Massage is not necessary and can damage underlying tissue. Massaging after a heparin injection can contribute to the formation of a hematoma. | ||
| 16. Do not recap the needle. Apply the safety shield or needle guard on needle and dispose in a sharps container. | Safety shields and needle guards help prevent accidental needle-stick injuries. | ||
| 17. Dispose of supplies; remove gloves and perform hand hygiene. | This reduces the risk of infection and the spread of microorganisms. | ||
| 18. Document procedure and findings according to agency policy. | Timely documentation ensures patient safety. | ||
| 19. Evaluate patient response to medication. | It is important to evaluate the therapeutic effect of the medication and assess for adverse effects. | ||
| Data source: ATI, 2015b; Berman & Snyder, 2016; Brookside Associates, 2015b; Clayton et al., 2010; National Institute of Health Clinical Center, 2015; Ogston-Tuck, 2014b; Perry et al., 2014 |
Critical Thinking Exercises
- Why should a health care provider rotate sites with a heparin SC injection, but only rotate within a site with insulin SC injections?
- What are three risks associated with administering insulin and heparin subcutaneously?