Overall Questions For Exam #4

Question 1

Why does acyclovir only affect viruses and not humans?

Answer 1

Acyclovir is an antiviral medication used to treat infections caused by viruses( herpes, Epstein-Barr virus, etc.) It only affects viruses because the drug is selectively toxic to viral DNA polymerase, it targets and inhibits replication of virus, without causing harm to human cells.

Question 2

What is the ELISA test?And what does it stand for?

Answer 2

ELISA (enzyme-linked immunosorbent assay)
A group of serological tests that use enzyme reactions as indicators

Question 3

Extra credit:
give examples of how antibiotics become resistant, what causes bacteria to become resistant to antibiotics?

Answer 3

Variety of mutations can lead to antibiotic resistance:
-overuse & misuse of antibiotics include
-outdated/weakened antibiotics
-Antibiotics in animal feed
-using someone else’s antibiotics leaves body susceptible to mutants.

Question 4

How does MHC affect APC?

Answer 4

MHC molecules are essential for the ability of APCs to present antigens to T cells. MHC molecules on the surface of APCs affects ability of T cells to recognize/respond to antigens.

Question 5

What is found on both skin and mucous membranes?

Answer 5

Skin & mucous membranes include:
Epithelial cells
Glands that secrete sweat & mucus
Dendritic cells
Immune cells

Question 6

What cell crosses capillary wall?

Answer 6

WBCs (leukocytes) are able to cross capillary walls through diapedesis

Question 7

Which immunoglobulin crosses the placenta?

Answer 7

IgG is the only immunoglobulin that crosses the placenta.

Question 8

What are the characteristics of antibodies?

Answer 8

Characteristics: 1. Specificity 2. Diversity 3. Affinity 4. Reusability 5. Ability to activate immune responses. 6. Immunological memory

Question 9

What antibodies can do:

Answer 9

• neutralize pathogens, opsonization, complement activation, antibody- dependent cell mediated cytotoxicity, provides passive immunity
  OVERALL: protects body from harmful foreign substances

Question 10

What antibodies can’t do:

Answer 10

Can’t directly kill pathogens, can’t target/eliminate cancer cells in their own, can’t cross blood brain barrier/ reach pathogens in CNS, can’t prevent viral infections from entering host cells but they can neutralize viruses before they enter host cells

Question 11

What would be found on the dermis of the skin?

Answer 11

Dermis of skin contains blood vessels, hair follicles, sweat glands, sebaceous glands, nerve endings, collagen&elastin fibers

Question 12

Third line of defense: specialized lymphocytes:

Answer 12

T&B cells

Question 13

Clonal selection
B cells become activated when?

Answer 13

an Ag reacts w specific receptors on its surface

Question 14

T cell- independent antigens stimulate….

Answer 14

B cells directly
- larger, repeating
- exogenous

Question 15

T-dependent Ags require help of 1____ & 2_____ to stimulate 3____

Answer 15

1 Antigen presenting cells (APCs)
2 T helper cells
3 B cells
* phagocytized by a phagocyte
* smaller not as numerous
* endogenous

Question 16

Stimulates TH cells:

Answer 16

Interleukin-1

Question 17

Activates TH, B, TC, and NK cells

Answer 17

Interleukin-2

Question 18

Differentiation of CD4 cells

Answer 18

Interleukin-12

Question 19

Stimulate macrophage activity:

Answer 19

γ- interferon
(Gama)

Question 20

Induce migration of leukocytes to infection

Answer 20

Chemokines

Question 21

Cell mediated immunity involves

Answer 21

Direct action of T cells

Question 22

• T Helper Cells (TH) = CD4 cells

Answer 22

present T dependent Ags to B cells, stimulate other T & B cells

Question 23

• T Cytotoxic Cells (TC) = CD8 cells

Answer 23

differentiate into cytotoxic T Lymphocytes (CTL) which destroy target cells with perforin

Question 24

T Regulatory Cells (Treg)

Answer 24

suppress T cells against self subset of CD4 TH cells
formerly called T suppressor cells

Question 25

Known fact of Jenners research

Answer 25

Known: smallpox is more dangerous than variolation, and cowpox is less dangerous than variolation

Question 26

Jenners hypothesis

Answer 26

Infection with cowpox gives immunity to smallpox

Question 27

Jenners test

Answer 27

If variolation after infection with cowpox fails to produce a small pocks infection, immunity to smallpox has been achieved

Question 28

Jenners consequence

Answer 28

Immunity to smallpox can be induced much more safely than by variolation

Question 29

Brief history of immunization
Chinese noticed children who recovered from smallpox did not contract the disease again. They infected children with material from a small pox scab to induce immunity.
This process is known as ??

Answer 29

Variolation
Variolation spread to England and America, but was stopped because of risk of death

Question 30

Answer 30