21. All three pathways cause activation of the C3 protein, which splits into two
fragments, C3b and C3a. What do these fragments do?
22. C3b cleaves C5 into two parts:
23. Name the four cardinal signs of inflammation:
1. _________________________
2. _________________________
3. _________________________
4. _________________________
1. Prevents _________________________
2. Disposes of _________________________
3. Sets the stage for _________________________
1. _________________________, which causes redness and heat
2. _________________________, which causes swelling and, thus, pain
26. These chemical mediators activate cell adhesion molecules on endothelial cells.
______________ is the process by which neutrophils and monocytes bind to these
27. The leakiness of the capillaries allows plasma and proteins to leak into the injured
area. What three important classes of proteins enter the affected area?
1. _________________________
2. _________________________
3. _________________________
28. In addition to the complement system, other chemicals act as inflammatory media-
tors:
29. Bacterial components and cytokines act as ______________, which cause the body’s
thermostat to set its temperature higher, thus causing a/an ______________. This
Immune System:
Common Characteristics of B and T Cells
1. Shared features of B and T lymphocyte function include:
a. ________________________________________________________________________
2. Lymphocytes must distinguish between normally occurring internal antigens called
3. Specificity of B and T cells depends on their ability to recognize ___________
______________. They have the ability to do this because their surface is covered
4. The antigen receptor on a B cell is an immunoglobulin, which is Y-shaped and
basically a membrane-bound ______________ .
5. The T cell receptor recognizes antigen fragments housed in cell membrane proteins
called “_________________________” (_______) proteins.
6. The immune system can develop receptors for a specific antigen before that antigen
7. Our bodies make approximately ______________ different types of lymphocyte anti-
gen receptors. With only 25,000 different genes in our body, how can so many anti-
gen receptors be made?
____________________________________________________________________________
9. The ______________ and ______________ are primary lymphoid organs because the
B and T cells originate and/or mature in these organs. To become immunocompe-
11. T cells recognize antigens by binding to _______ proteins on an antigen-presenting
12. If a T cell recognizes this protein (the one mentioned above), it is then tested for
recognition of _________________________, the body’s own antigens. This process
13. If lymphocytes attack the body’s own cells, this will result in a/an
_________________________ disease.
14. Below is a list of diseases that result when the immune system attacks the body’s
own cells. State what cells the immune system is attacking in each disease.
15. These diseases may occur as a result of what three events mentioned in this Topic?
1. ________________________________________________________________________
2. ________________________________________________________________________
3. ________________________________________________________________________
____________________________________________________________________________
17. The T cell becomes activated when it encounters its antigen. The T cell then
1. ______________ cells, which attack the antigen-presenting cell
18. When an antigen activates a B cell, the cloned _________________________ (effector
cells) secrete antibodies in about seven days. This is known as the ______________
immune response.
19. When exposed to the same antigen again, the ______________ B cells generate a/an
20. The purpose of _________________________ is to generate memory cells, thus pro-
tecting us without the risk of getting sick.
Immune System:
Humoral Immunity
1. Antibodies can be found on the plasma membrane of ______________ (where they
2. Antibodies consist of two types of polypeptide chains:
3. Each chain has a ______________ region that is unique for each antigen and a/an
4. Each arm of the Y-shaped antibody has identical _________________________ sites.
The shape of these sites must match the shape of the _________________________
on the antigen in order to bind.
5. The stem of the Y-shaped antibody determines how it will interact with other com-
ponents of the immune system. Complete the following examples given in this
Topic:
6. Name the five classes of antibodies, each with a distinct type of stem:
1. _________________________
2. _________________________
3. _________________________
4. _________________________
5. _________________________
7. Complete the list of four contributions of IgG antibodies:
1. Constitutes the _________________________ of circulating antibodies
4. Can be transferred from one individual to another (example of
______________________ immunity)
8. Match the characteristics listed below to the correct antibody. Choose either IgM
or IgA.
These antibodies are found in secretions of tears, sweat, and saliva _____
9. IgE is produced as a result of the body’s infestation with _________________________.
Which white blood cell type is important to combat this infestation? ______________
10. In modern, industrialized countries, the most common function of IgE is its role in
11. The first exposure to an antigen is called _________________________. As a result,
12. As a result of the actions of the chemical released in question 11, the affected per-
son gets a runny nose (due to _________________________) and has difficulty
breathing (due to _________________________).
14. Allergic reactions to peanuts can be very serious, causing a systemic allergic
reaction known as _________________________.
16. There are four general ways that antibodies work (to remember: PLAN). Fill in the
following:
1. P—act as opsonins to destroy pathogens by _____________
2. L—initiate complement activation, resulting in _____________ of the pathogen
1. B cells respond to _____________ antigens.
3. B and T cells continually _____________ and congregate in the
_________________________ (where the antigens are concentrated).
18. When naïve B cells encounter their specific antigen (usually in the _____________
19. B cells then migrate deeper into the cortex, where T cells are found. In most cases,
full activation of B cells requires the assistance of _____________ cells. These are
known as “T cell-_____________ antigens.”
20. If the T cell recognizes the antigenic fragment bound to the _____________ protein
21. _____________ cells are not needed for certain antigens such as polysaccharides.
These antigens are known as “T cell-_____________ antigens.” These are generally
(stronger or weaker) responses.
22. When the antigen has selected an appropriate B cell, the B cell will produce effector
1. _________________________; results in antibodies that are highly selective for
the antigen
3. _________________________; results in cells becoming plasma cells or memory
cells
24. Humoral immunity can be acquired either actively or passively. Define each and
give an example of the naturally and artificially acquired forms.
Active Immunity: __________________________________________________________
Immune System:
Cellular Immunity
1. Cytokines are small proteins that transfer information within the immune system.
List the actions of cytokines given in this Topic:
2. Interleukin 1, a cytokine, acts as a chemical alarm to alert the immune system to
the presence of a pathogen. List the three actions given for interleukin 1 in this
Topic:
1. _________________________
3. Interleukin 2, released by helper T cells, causes proliferation of activated
lymphocytes. This process is called _________________________.
4. The two major classes of lymphocytes that mediate cellular immunity are based on
5. Below are the two major classes of cells with CD protein markers. List what the
cells become and what class of MHC proteins they bind.
6. The HIV virus binds to CD4 surface proteins and destroys the ______________
cells.
7. The _______ proteins are one major class of self-antigens. Thus, before an organ
8. ______________ cells circulate through the body searching for infected or cancerous
cells by examining the antigenic determinant on ______________ MHC proteins on
9. Unlike class I MHC proteins, which can be displayed on any nucleated cell, class II
MHC proteins are displayed only on select cells. Name the antigen-presenting cells
that have class II MHC proteins:
a. _________________________
10. Class II MHCs are produced in the _________________________ and pick up the
exogenous antigens when they fuse with the ______________.
12. Dendritic cells are responsible for activating most T cells. Choose the correct
answer for each of the following:
13. Exception: Normally, when cells express endogenous foreign antigens on class I
MCH proteins on their cell membrane, they are marked for destruction. This is not
14. List the two steps necessary for T cell activation:
1. ________________________________________________________________________
2. ________________________________________________________________________
15. Once T cells are activated they undergo proliferation (called ____________
16. Antigen-presenting cells will express co-stimulatory molecules when they have
been signaled by the ______________ defense mechanisms that an infection is pres-
17. There are two ways to induce a process of self-destruction in a cell, which is called
______________:
2. Natural killer cells look for the absence of ______________ and are thus able to
eliminate abnormal cells that cytotoxic T cells cannot detect.
19. The helper T cell can help activate the CD8 cell to become a/an ______________
T cell in two ways:
2. It secretes ______________ (including interleukin 2) to help activation.
20. T
H
1 cells secrete ______________ interferons, which increase the effectiveness of
21. Regulatory T cells suppress the activity of other T cells by direct