Chapter 21: Immune System

Question 0

Adaptive defenses include…

Answer 0

Humoral immunity (B cells) and cellular immunity (T cells)

Question 1

Includes surface barriers (skin, mucous membranes) and internal defenses (phagocytes, inflammation)

Answer 1

Innate defenses

Question 2

Antibodies (Ab) are also called…

Answer 2

immunoglobulins (Igs)

Question 3

Antibody structure

Answer 3

Consists of 4 polypeptides - 2 short “light chains” and 2 long “heavy chains” joined together by disulfide bonds.

Question 4

When each chain forms an antibody it has…

Answer 4

One variable (V) region and a constant (C) region.

Question 5

V regions of the heavy and light chains combine to form an _____ shaped to “fit” a specific antigenic determinant

Answer 5

Antigen-binding site

Question 6

Must have an antibody specific for each _____

Answer 6

Antigen

Question 7

The binding site on bacteria where the antibody can attach. “Lock and key”

Answer 7

Epitome

Question 8

The 5 major immunoglobulins (Igs) classes:

Answer 8

GAMDE

Question 9

IgM

Answer 9

The first Ig class secreted by plasma cells during the primary response. Exists as both a monomer and pentamer.

Question 10

IgA

Answer 10

Found in body secretions such as saliva, sweat, intestinal juice, and milk

Question 11

IgD

Answer 11

Found on the B cell surface

Question 12

IgG

Answer 12

The most abundant antibody in plasma

Question 13

IgE

Answer 13

Secreted within the mucous membrane and triggers cells to release histamine and other chemicals that mediate inflammation/allergic reaction

Question 14

B cells

Answer 14

Oversee humoral immunity

Question 15

T cells

Answer 15

Are non-antibody-producing lymphocytes that constitute the cellular arm of adaptive immunity

Question 16

Macrophages

Answer 16

Widely distributed throughout the lymphoid organs and CT in search of foreign substances

Question 17

Antigen-presenting cells

Answer 17

Macrophages and B cells
Engulf antigens and then present fragments of them, like signal flags, on their own surfaces where T cells can recognize them as MHC2

Question 18

All nucleated cells have _____

Answer 18

MHC1 (major histocompatibility complex)

Question 19

MHC proteins

Answer 19

Cell surface glycoproteins that identify a cell as self or “self-antigens”

Question 20

T cells come in 2 different forms:

Answer 20

T-killer cells

T-helper cells

Question 21

T-killer cells

Answer 21

Aka CD8 T cells, cytotoxic, recognizes MHC1/MHC2 on antigen presenting cells

Question 22

T-helper cells

Answer 22

Secrete chemicals “cytokines” that help the activity of other immune cells. They are essential in B cell antibody class switching, in the activation and growth of cytotoxic T cells, and in maximizing bactericidal activity of phagocytes such as macrophages.

Question 23

Natural killer cells (NKC)

Answer 23

Innate; like T killer cells however they recognize whether the cell carries MHC1 or not

Question 24

Apoptosis

Answer 24

Programmed cell death (suicide)

Question 25

+/- chemotaxis

Answer 25

Chemical trail, positive if cell follows the trail and negative if it goes away

Question 26

SUMMARY

Answer 26

1- virus enters body 2- macrophages/B cell recognize foreign substance 3- macrophages/B cell phagocytize virus & displays it as MHC2 4- T-helper cell sees MHC2 on B cell 5- T-helper cell releases cytokines, activate T-killers, and activates B cell 6- B cells differentiate between plasma cells or memory cells 7- T-killer cells can kill virus