Exam 2 - Chapter 15

Question 1

Humoral Immunity

Answer 1

Eliminates microbes from blood and tissue fluids. Involve B cells

Question 2

Cell-Mediated Immunity

Answer 2

Eliminates microbes from within a host cell, usually viruses or bacteria, and sometimes cancerous cells. Involve T cells

Question 3

Naive Lymphocyte

Answer 3

A lymphocyte that needs a confirmation signal before it can react to an invader

Question 4

Activated Lymphocyte

Answer 4

A B or T cell that once it knows the invader needs to be killed, it proliferates

Question 5

Effector Lymphocytes

Answer 5

Short lived cells that express certain traits to kill invaders

Question 6

Memory Lymphocytes

Answer 6

Long lived cells that recognize a past antigen and reacts quickly

Question 7

Plasma Cells (Effector B Cells)

Answer 7

Descendants of activated B cells, that make antibodies

Question 8

B Cell Receptor (BCR)

Answer 8

A version of the antibody the B cell is gonna make, except it’s stuck on its surface

Question 9

Cytotoxic T Cells

Answer 9

Destroy infected host cells that have viruses

Question 10

Helper T Cells

Answer 10

Direct and assist in the multiple immunity responses

Question 11

Regulatory T Cells

Answer 11

Surpress the immune response, so we don’t overreact to stupid things like pollen

Question 12

Secondary Lyphoid Organs

Answer 12

Sites where lymphocytes gather to contact antigens

Question 13

Peyer’s Patches

Answer 13

Samples intestinal contents via M cells and dendritic cells

Question 14

Mucosa-Associated Lymphoid Tissue (MALT)

Answer 14

Mucosal immunity prevents microbial invasion via mucous membranes

Question 15

Skin-Associated Lymphoid Tissue (SALT)

Answer 15

Lymphoid tissues under skin

Question 16

Primary Lymphoid Organs

Answer 16

Bone and Thymus. Where B and T cells mature. Once any lymphocytes are mature, they migrate to secondary lymphoid organs and wait for any antigens that might invade

Question 17

Immunogen

Answer 17

An antigen that elicits an immune respone

Question 18

Immunoglobulin (Ig) Classes

Answer 18

IgM, IgG, IgA, IgD, IgE

Question 19

IgM

Answer 19

5–13% of circulating antibodies
First class produced during primary response
Principal class produced in response to some T-independent antigens
Pentamer
Five monomeric subunits give 10 antigen-binding sites
Aggregates very effectively
Large size prevents crossing from bloodstream to tissues
Primary role in bloodstream infections
Most efficient class in triggering classical pathway of complement system

Question 20

IgG

Answer 20

80–85% of total serum immunoglobulin
Also exits bloodstream to enter tissues
Provides longest-term protection: half-life is 21 days
Generally first and most abundant circulating class produced during secondary response
Protect via neutralization, aggregation, opsonization, complement activation, and antibody-dependent cellular cytotoxicity
Transported across placenta to fetus’s bloodstream
Women cautioned to avoid pathogens to which they lack immunity (e.g., Toxoplasma gondii in raw meat, cat feces)
Maternal IgG protects fetus and newborn
Degrade gradually over 6 month period
Infant begins producing
IgG found in colostrum (first breast milk); absorbed by newborn’s intestinal tract

Question 21

IgA

Answer 21

Monomeric form is 10–13% of serum antibodies
Most IgA is a dimer: secretory IgA (sIgA)
IgA is most abundant immunoglobulin class produced
Secreted form important in mucosal immunity
Gastrointestinal, genitourinary, and respiratory tracts
Xecretions including saliva, tears, breast milk
Protects breast-fed infants against intestinal pathogens
Protection primarily via neutralizing toxins, viruses and interfering with attachment of microbes to host cells
Produce by plasma cells of mucosa-associated lymphoid tissue (MALT); secretory component (polypeptide) added to attach antibody to mucus

Question 22

IgD

Answer 22

Less than 1% of serum immunoglobulins
Involved with development and maturation of antibody response
Function in serum not clearly defined

Question 23

IgE

Answer 23

Barely detectable in normal blood
Tightly bound via Fc region to basophils and mast cells
Allows these cells to detect, respond to antigens
Antigen binds to two adjacent IgE molecules carried by mast cell, cell releases histamine and other inflammatory mediators
Basophils and mast cells also release chemicals when IgE binds to normally harmless foods, dusts, pollens, yielding allergic reactions of coughing, sneezing, swelling
Some allergic (hypersensitivity) reactions can be life-threatening