Assignment 1

Question 1

role of immune system in host defense

Answer 1

provides defense against foreign antigens

Question 2

define tolerance

Answer 2

adaptive immunity of the body distinguishing self from non-self such that it destroys non-self and not self

Question 3

consequences of loss of tolerance

Answer 3

leads to autoimmunity, a disorder in which self molecules are interpreted as foreign and hence trigger immune responses

Question 4

difference between central and peripheral tolerance

Answer 4

B cells undergo central tolerance in the bone marrow and T cells undergo central tolerance in the thymus. Peripheral tolerance are tolerance induction of those that escaped tolerance induction in the bone marrow or thymus

Question 5

properties of antigens

Answer 5

foreign, chemically complex, molecular weight greater than 6kD

Question 6

molecules that are most immunogenic in descending order

Answer 6

proteins > polysaccharide > nucleic acids > lipids

Question 7

three terms that are used to refer to the component of the antigen with which receptors on immune cells interact

Answer 7

epitope, antigenic determinant, determinant

Question 8

three chemical barriers to infections

Answer 8

lysozyme, spermine, acidic pH of stomach

Question 9

two physical barriers to infections

Answer 9

skin and mucosal linings

Question 10

4 defining characteristics to adaptive immune system

Answer 10

exquisite specificity, lag time, memory, and adaptivity

Question 11

4 defining characteristics of innate immune system

Answer 11

no exquisite specificity, no lag time, no memory, no adaptivity

Question 12

cells of innate immunity

Answer 12

phagocytes (macrophages and neutrophils), natural killer (NK) cells, dendritic cells, mast cells, basophils, eosinophils

Question 13

cells of adaptive immunity

Answer 13

lymphocytes (T and B cells)

Question 14

components of secondary lymphoid tissue

Answer 14

lymph nodes, tonsils and adenoids, spleen, and malt (mucosal associated lymphoid tissue)

Question 15

what are primary lymphoid tissue

Answer 15

bone marrow and thymus

Question 16

role of bone marrow and thymus

Answer 16

Under the influence of the local microenvironment some of the lymphoid precursors will give rise to mature B cells, while other lymphoid precursors will leave the bone marrow and migrate to the thymus and differentiate to various T cell subsets

Question 17

role of secondary lymphoid tissue

Answer 17

major sites of adaptive immune responses - initial immune response is determined by the mode of antigen entry

Question 18

what happens in the lymph nodes

Answer 18

afferent lymphatics penetrate the connective tissue that encapsulates the lymph node and empty their contents into the subcapsular sinuses

Question 19

difference between primary and secondary follicles of lymph nodes

Answer 19

secondary have germinal centers while primary does not

Question 20

what do primary follicles contain

Answer 20

mature resting B cells

Question 21

what is in a germinal center

Answer 21

antigen activated B cells

Question 22

types of cells present in between and below follicles

Answer 22

T cells interspersed with dendritic cells

Question 23

what does the medulla contain

Answer 23

dendritic cells, macrophages, plasma cells

Question 24

what does the nodes consist of

Answer 24

outer cortex, medulla, paracortex

Question 25

what is present in the outer cortex of the lymph node

Answer 25

follicles both the primary and secondary

Question 26

tissues in spleen

Answer 26

white pulp and red pulp

Question 27

predominant T cell region in spleen

Answer 27

white pulp

Question 28

white pulp area surrounding the central arteries and arterioles is called

Answer 28

PALS - periarterial lymphatic sheath

Question 29

predominant B cell region in spleen

Answer 29

primary and secondary follicles that exit as outgrowth of PALS

Question 30

what does the marginal zone contain

Answer 30

macrophages and dendritic cells

Question 31

what is a mucosa associated lymphoid tissue (MALT)

Answer 31

unencapsulated lymphoid tissue present in regions underlying the mucosal areas

Question 32

what is GALT

Answer 32

gut associated lymphoid tissue - MALT that has been well described

Question 33

in GALT, regions where there are no goblet cells and mucus layer is sparse or absent

Answer 33

FAE - follicle associated epithelium

Question 34

organized aggregates of follicles present in GALT

Answer 34

peyer’s patches

Question 35

site of follicles and immune cells including phagocytic cells, dendritic cells, and lymphocytes

Answer 35

lamina propria

Question 36

microbes enter MALT via what type of specialized epithelial cells that is present in the mucosal luminal lining

Answer 36

M cells

Question 37

what is BALT

Answer 37

bronchus associated lymphoid tissue - well define MALT lymphoid tissue

Question 38

If antigen is carried via the lymphatics, the initial site of the adaptive immune response will be

Answer 38

lymph node

Question 39

If antigens are blood-borne, the initial site of the adaptive immune response will be

Answer 39

spleen

Question 40

if antigens enter via mucosal tissue, the initial site of the adaptive immune response will be

Answer 40

MALT

Question 41

5 antibody isotypes

Answer 41

IgG, IgA, IgM, IgE, IgD (think GAMED)

γ, α, μ, ε, δ (all start with first letter of respective antibody)

Question 42

bifunctional molecules whose polypeptide chains define an antigen binding site and a site carries out the biological activity of the molecule

Answer 42

antibodies aka immunoglobulins (Igs)

Question 43

family of proteins that facilitate elimination of microorganisms, particularly extracellular bacteria

Answer 43

complement

Question 44

small peptides secreted mainly by activated leukocytes

Answer 44

cytokines/interleukines

Question 45

molecules that were first identified by nature of their ability to induce leukocyte accumulation in tissue sites of inflammation

Answer 45

chemokines

Question 46

molecules that attract cells to a particular region

Answer 46

chemoattractant