Final Exam Study Guide

Question 1

innate immune response

Answer 1

present at birth, provide nonspecific resistance to infection

Question 2

adaptive immune response

Answer 2

specific, must be acquired

Question 3

first line of defense

Answer 3

Nonspecific

Physical barriers: skin, tears, coughing, sneezing

Chemical barriers: low pH, lysozyme, digestive enzymes

Genetic barriers: resistance inherent in genetic makeup of host (pathogen cannot
invade)

Question 4

second line of defense

Answer 4

Mostly nonspecific

Phagocytosis, inflammation, fever, interferon, complement

Question 5

third line of defense

Answer 5

Specific

T lymphocytes, B lymphocytes, antibodies

Question 6

components of a healthy immune system

Answer 6

1. Reticuloendothelial system (RES)
2. Extracellular fluid (ECF)
3. Bloodstream
4. Lymphatic system

Question 7

functions of a healthy immune system

Answer 7

Surveillance

Recognition and differentiation of normal versus foreign material

Attack against and destruction of entities deemed to be foreign

Question 8

plasma vs. serum

Answer 8

Serum: liquid portion of blood after a clot has formed (minus clotting factors)

Plasma: 92% water, metabolic proteins, globulins, clotting factors, hormones, and other chemicals and gases to support normal physiological functions

Question 9

hematopoiesis

Answer 9

production of blood cells

Question 10

different types of blood cells and origins

Answer 10

Platelets (thrombocytes): formed elements in circulating blood that are not whole cells

Red blood cells (RBCs): develop from bone marrow stem cells, lose nucleus, simple biconcave sacs of hemoglobin

Leukocytes or white blood cells (WBCs): responsible for immune function

Question 11

myeloid stem cells

Answer 11

derived from hematopoietic stem cells. They undergo differentiation to produce precursors of erythrocytes, platelets, dendritic cells, mast cells, monocytes, and granulocytes

Question 12

lymphoid stem cells

Answer 12

Lymphocytes – 20-35%, specific immune response

B-cell and T-cell

Lymphocytes are mature, infection-fighting cells that develop from lymphoblasts, a type of blood stem cell in the bone marrow. Lymphocytes are the main cells that make up lymphoid tissue, a major part of the immune system. Lymphoid tissue is found in lymph nodes, the thymus gland, the spleen, the tonsils, and adenoids.

Question 13

granular vs. agranular leukocytes

Answer 13

Granulocytes: lobed nucleus (neutrophils, eosinophils, basophils)

Agranulocytes: unlobed, rounded nucleus (lymphocytes, monocytes, macrophages)

Question 14

inflammation

Answer 14

Reaction to any traumatic event in the tissues that attempts to restore homeostasis.

Helps to clear away invading microbes and cellular debris left by immune reactions.

Redness – increased circulation and vasodilation in response to chemical mediators

Warmth – heat given off by the increased blood flow

Swelling – increased fluid in the tissue as blood vessels
dilate – edema; WBC’s, microbes, debris, and fluid collect to form pus; prevents spread of infection

Pain – stimulation of nerve endings

Question 15

interferon

Answer 15

Small protein produced by certain WBCs and tissue cells
Three major types of IFNs:
• Interferon alpha – product of lymphocytes and macrophages
• Interferon beta – product of fibroblasts and epithelial cells
• Interferon gamma – product of T cells
All produced in response to viruses, RNA, immune products,
and anatigens

Question 16

fever

Answer 16

Initiated by circulating pyrogens which reset the
hypothalamus to increase body temperature; signals muscles
to increase heat production and vasoconstriction
• Exogenous pyrogens – products of infectious agents;
endotoxin
• Endogenous pyrogens – liberated by monocytes,
neutrophils, and macrophages during phagocytosis;
interleukin-1 (IL-1) and tumor necrosis factor (TNF)

Question 17

complement

Answer 17

Consists of 26 blood proteins that work in concert to destroy
bacteria and viruses
Complement proteins are activated by cleavage (cascade
reaction)
Pathways
• Classical – activated by the presence of antibody bound to
microorganism
• Lectin pathway – nonspecific reaction of a host serum protein
that binds mannan
• Alternative – begins when complement proteins bind to normal
cell wall and surface components of microorganisms

Question 18

phagocytosis

Answer 18

General activities of phagocytes:
1. To survey tissue compartments and discover microbes,
particulate matter, and dead or injured cells
2. To ingest and eliminate these materials
3. To extract immunogenic information from foreign matter

Question 19

examples of phagocytic and non-phagocytic leukocytes

Answer 19

Phagocytes: Neutrophils, Eosinophils, and Macrophages

Non-phagocytes: Mast cells, Basophils

Question 20

antigens (and examples)

Answer 20

molecules that stimulate response by T and B cells

Question 21

different types of antigens

Answer 21

alloantigen: a genetically determined antigen present in some but not all individuals of a species
allergen: An allergen is a substance that can cause an allergic reaction.
superantigen: potent T cell stimulators
autoantigens: produced by the host.

Question 22

main features of adaptive immune response

Answer 22

Specificity – antibodies produced, function only against
the antigen that they were produced in response to

Memory – lymphocytes are programmed to “recall” their
first encounter with an antigen and respond rapidly to
subsequent encounters

Question 23

structure (parts) of an antibody molecule and their functions

Answer 23

An antibody, also known as an immunoglobulin, is a Y-shaped structure which consists of four polypeptides — two heavy chains and two light chains. This structure allows antibody molecules to carry out their dual functions: antigen binding and biological activity mediation.

Question 24

difference between B and T cell receptors

Answer 24

B-cell receptors – bind free antigens

T-cell receptors – bind processed antigens together with
the MHC molecules on the cells that present antigens to
them

Question 25

examples of T Lymphocytes and their functions

Answer 25

cytotoxic: (Tc cells) have a co-receptor called CD8 on their cell surface. CD8 partners with the T cell receptor and with MHC class I molecules, acting as a sort of bridge
helper: They help activate B cells to secrete antibodies and macrophages to destroy ingested microbes, but they also help activate cytotoxic T cells to kill infected target cells.
regulator: (TReg) essential for maintaining peripheral tolerance, preventing autoimmune diseases and limiting chronic inflammatory diseases.

Question 26

examples of B Lymphocytes and their functions

Answer 26

transitional: Transitional B cells mark the crucial link between bone-marrow (BM) immature and peripheral mature B cells.

naïve: once exposed to an antigen, either becomes a memory B cell or a plasma cell.

plasma: A plasma cell releases antibodies that circulate in the blood and lymph, where they bind to and neutralize or destroy antigens.
memory: They form memory cells that remember the same pathogen for faster antibody production in future infections.

Question 27

difference between antigen, hapten, and epitopes

Answer 27

Antigens are any substance that binds specifically to an antibody or a T-cell receptor.

Hapten is a molecule that reacts with specific antibody but is not immunogenic by itself, it can be made immunogenic by conjugation to a suitable carrier.

An epitope, also known as antigenic determinant, is the part of an antigen that is recognized by an antibody, B-cell receptor or T-cell receptor.

Question 28

opsonization

Answer 28

When coated with antibodies microorganisms or other particles are more readily recognized by phagocytes which engulf and dispose of them.

Question 29

neutralization

Answer 29

Antibodies fill the surface receptors on a virus or the active site on a bacterial protein, which prevents them from attaching to their target cells.

Question 30

agglutination

Answer 30

Because each antibody has two identical binding sites, cells can be bound together to form large clumps. This renders the microbe immobile, increasing the rate at which they are phagocytized.

Question 31

complement fixation

Answer 31

Antibodies bound to the surface of a microbe can activate the complement system, leading to lysis of the cell, and some viruses.

Question 32

different classes of antibodies

Answer 32

IgG: most prevalent, produced by plasma and memory cells

IgM: first class synthesized

IgA: circulates in blood, dimer in mucous and serous secretions

IgD: serves as a receptor for antigen on B cells

IgE: involved in allergic responses and parasitic worm infections

Question 33

difference between the primary and the secondary (anamnestic) antibody responses

Answer 33

A primary (1°) immune response is the response that occurs following the first exposure to a foreign antigen.

A secondary (2°)/anamnestic immune response occurs following subsequent exposures.

Question 34

class of the first antibody secreted in the blood

Answer 34

IgM

Question 35

class of the most abundant antibody secreted in the blood

Answer 35

IgG

Question 36

sites of B and T cell maturation

Answer 36

B cells mature in the bone marrow.

T cells mature in the thymus.

Question 37

examples of the primary and the secondary lymphoid organs

Answer 37

Primary lymphoid organs: These organs include the bone marrow and the thymus. They create special immune system cells called lymphocytes.

Secondary lymphoid organs: These organs include the lymph nodes, the spleen, the tonsils and certain tissue in various mucous membrane layers in the body (for instance in the bowel).

Question 38

difference between humoral and cell mediated immunity

Answer 38

The major difference between humoral and cell-mediated immunity is that humoral immunity produces antigen-specific antibodies

Cell-mediated immunity does not. T lymphocytes, on the other hand, kill infected cells by triggering apoptosis.

Question 39

Type I hypersensitivity reaction

Answer 39

Type I: reaction mediated by IgE antibodies.

allergen, anaphylaxis

Question 40

Type II hypersensitivity reaction

Answer 40

Type II: cytotoxic reaction mediated by IgG or IgM antibodies.

(wrong blood type)

Question 41

Type III hypersensitivity reaction

Answer 41

Type III: reaction mediated by immune complexes.

antitoxin, antivenom

Question 42

Type IV hypersensitivity reaction

Answer 42

Type IV: delayed reaction mediated by cellular response.

contact dermatitis

Question 43

Herd Immunity

Answer 43

Immune individuals will not harbor it, reducing the occurrence of pathogens – herd immunity

Less likely that a nonimmunized person will encounter the
pathogen

Question 44

examples of the different types of vaccines

Answer 44

Live attenuated bacteria: tuberculosis, typhoid

Acellular vaccines: anthrax, meningitis, pneumonia

Inactivated vaccines: hepatitis A, flu, polio, rabies.

Live-attenuated vaccines: measles, rotavirus, smallpox, chickenpox, yellow fever

Subunit, recombinant, polysaccharide, and conjugate vaccines: Hib, hepatitis B, HPV, shingles.

Toxoid vaccines: diphtheria, tetanus

DNA vaccines: lyme diease, hepatitis C, herpes, influenza, tuberculosis, malaria.