Immune System

Question 1

3 step lymphatic pathway

Answer 1

1) Fluid and lipids from the interstitial fluid are absorbed into lymph capillaries.
2) These then drain into larger lymph vessels.
3) These then drain through lymph ducts into the vena cava of the circulatory system.

Question 2

Functions of the lymphatic system

Answer 2

The lymph system helps return fluid from the interstitial fluid to the circulatory system.
Also functions in immune response and fat absorption.

Question 3

Three effects of antibody binding

Answer 3

Question 4

Innate vs adaptive immunity

Answer 4

Innate immunity describes non-specific defenses including physical barriers like skin and mucus membranes, and the complement system.

Adaptive immunity describes pathogen-specific defenses and is divided into humoral (B-cells) and cell-mediated (T-cells) immunity.

Question 5

Four principles of immunity

Answer 5

Question 6

Function:
Part of the lymphoid system. Helps recycle old red blood cells and activates B-cell immune response.

Immune activation:
Contains large amount of macrophages to attack any antigens found in blood that filters through the spleen.

Answer 6

Spleen

Question 7

Mature in the Thymus after production in bone marrow.
Primarily coordinates cell-mediated (aka cytotoxic) immunity.

Answer 7

T-lymphocytes

Question 8

Responds to MHC-I antigen on infected cells and destroys the presenting cell.
Expresses CD8+ receptor.

Answer 8

Cytotoxic T-cells

Question 9

Recognizes MHC-II antigen on antigen-presenting cells and then activates other immune cells.
Expresses CD4+ receptor.

Answer 9

Helper T-cells

Question 10

Decreases immune response after infection resolves. Defects can lead to autoimmune disease.

Answer 10

Suppressor T-cells

Question 11

Displays antigen to cytotoxic T-cells. Found in all nucleated cells.

Answer 11

MHC-I

Question 12

Displays antigen to helper T-cells. Found in antigen-presenting cells (like dendritic cells, macrophages, etc) specifically.

Answer 12

MHC-II

Question 13

General structure of antibody structure

Answer 13

Y-shaped consisting of 2 heavy chains and 2 light chains, connected by disulfide bonds.

Question 14

The base of the antibody structure contains the constant (Fc) region.
This region determines the class of the antibody (for example IgG or IgM).

Answer 14

Constant region of antibody structure

Question 15

The tips of the antibody structure contain the hypervariable region, and at the end is the antigen-binding (Fab) region.
Generates a highly specific sequence to antigens (like in the case of re-infection).

Answer 15

Variable region of antibody structure

Question 16

Ingest the pathogen, processes the pathogen, and then acts as antigen-presenting cell with MHC-II.

Answer 16

macrophages

Question 17

Phagocytic cells that are activated by bacteria.

Answer 17

Neutrophils

Question 18

Attacks abnormal or pathogenic cells (like cancer cells or virally infected cells) instead of attacking the pathogen itself.

Answer 18

Natural killer cells

Question 19

Functions in inflammatory response. Releases histamine triggered by an allergic response.

Answer 19

Mast cells

Question 20

Antigen-presenting cells that contact the external environment. Located on skin and mucus membranes.

Answer 20

dendritic cells

Question 21

Matures in the bone marrow and are activated in the spleen and lymph nodes.
Responsible for humoral immunity which works through antibody production by B-cells.

Answer 21

B-lymphocytes

Question 22

B-cell activation

Answer 22

When exposed to antigens, B-cells will form plasma cells and memory cells.

Question 23

Secrete antibodies, which are immunoglobulins that target antigens.

Answer 23

Plasma cells

Question 24

Persistent after infection. Trigger a stronger, more rapid response when the same pathogen is seen again.

Answer 24

Memory B-cells