Chapter 16: Lymphatic System

Question 1

adaptive defense

Answer 1

resistance to particular pathogens or to their toxins/metabolic by-products

Question 2

adaptive defense is…

Answer 2

3rd line of defense

Question 3

antigens

Answer 3

non self molecules that can elicit an immune response

Question 4

adaptive responses are carried out by __

Answer 4

lymphocytes & macrophages that can recognize specific antigens

Question 5

2 types of adaptive defense

Answer 5

1. cellular immune response
2. humoral immune response

Question 6

types of antigens (4)

Answer 6

• proteins
• polysaccharides
• glycolipids
• glycoproteins

Question 7

T lymphocytes

Answer 7

• specialized in thymus
• make up 70-80% of circulating lymphocytes
• some settle in lymphatic organs (white pulp, lymph nodes, thoracic duct)

Question 8

B lymphocytes

Answer 8

• released from bone marrow
• make up 20-30% of lymphocytes
• abundant in lymph nodes, spleen, bone marrow, intestinal lining

Question 9

what does T cell activation require?

Answer 9

antigenic fragments to be attached to antigen presenting cell such as B cells, macrophages, etc

Question 10

APC

Answer 10

antigen presenting cell; accessory cell

Question 11

what does APC do to antigen?

Answer 11

phagocytizes antigen, digests it, & displays antigenic fragments on its own cell membrane, bound to protein that is part of the MHC or HLA

Question 12

MHC

Answer 12

major histocompatibility complex

Question 13

HLA

Answer 13

human leukocyte antigens

Question 14

what happens when T cell encounters APC displaying antigenic fragments?

Answer 14

it can recognize antigen as foreign substance; T cell now activated

Question 15

what can T cells secrete?

Answer 15

cytokines

Question 16

cytokines

Answer 16

enhance some cellular responses to antigens

Question 17

T cell types (3)

Answer 17

1. helper
2. cytotoxic
3. memory

Question 18

helper T cells

Answer 18

activate other cells; help B cells produce antibodies

Question 19

cytotoxic T cells

Answer 19

attack virally infected/cancerous cells

Question 20

memory T cells

Answer 20

provide future immune protection

Question 21

types of cytokines (4)

Answer 21

1. colony stimulating
2. interferons
3. interleukins
4. tumor necrosis factor

Question 22

colony stimulating cytokine

Answer 22

stimulate bone marrow to produce lymphocytes

Question 23

interferon cytokine

Answer 23

block viral replication, stimulate macrophages, stimulate B cells to produce antibodies, attack cancer cells

Question 24

interleukin cytokine

Answer 24

control lymphocyte differentiation & proliferation

Question 25

tumor necrosis factor

Answer 25

stop tumor growth, releases growth factors, causes fever, stimulates lymphocyte differentiation

Question 26

what must occur for B cells to respond?

Answer 26

proper cytokines are released from helper T cells; B cells respond by proliferating, enlarging clone of identical cells

Question 27

what happens to B cells when they respond?

Answer 27

- some become memory B cells - some differentiate into plasma cells, which produce & secrete larger globular proteins called antibodies

Question 28

humoral/antibody-mediated immune response

Answer 28

antibodies are carried by the blood to infection site

Question 29

what do both B cells & T cells require

Answer 29

proper activation; helper T cells secrete cytokines to activate B cells to proliferate

Question 30

antibodies

Answer 30

- globular proteins - also called immunoglobulins - y shaped proteins; composed of 4 AA chains - make up gamma globulin fraction of plasma proteins

Question 31

5 major types of antibodies

Answer 31

1. IgA (80%) 2. IgG (13%) 3. IgM (6%) 4. IgE (<1%) 5. IgD (<1%)

Question 32

IgG

Answer 32

plasma and tissue fluid; defends against bacteria and activates complement

Question 33

IgA

Answer 33

exocrine gland secretions; defends against bacteria and viruses

Question 34

IgM

Answer 34

plasma; reacts with antigens on some red blood cell membranes following mismatched blood transfusions, and activates complement

Question 35

IgD

Answer 35

surface of most B lymphocytes; B cell activation

Question 36

IgE

Answer 36

exocrine gland secretions; promotes inflammation and allergic responses