Immunology

Question 1

First line of defense

Answer 1

First line of defense – any barrier that blocks invasion at the portal of entry – 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 2

Innate, humoral, cell-mediated immunity

Answer 2

Innate, natural defenses: present at birth, provide
nonspecific resistance to infection

Adaptive immunities: specific, must be acquired

Question 3

Lymphoid nodes

Answer 3

Small, encapsulated, bean-shaped organs along lymphatic channels and large blood vessels of the thoracic and abdominal cavities

Question 4

Thymus

Answer 4

High growth and activity until puberty, then begins to shrink. Site of T-cell maturation.

Question 5

Spleen

Answer 5

Nestled below the diaphragm and left of the stomach. Structurally similar to lymph node; filters circulating blood to remove worn out RBCs and pathogens.

Question 6

GALT

Answer 6

GALT—gut-associated lymphoid tissue (Peyer’s patches)

Question 7

Eosinophils

Answer 7

Eosinophils – 1-3% - orange granules and bilobed nucleus; destroy eukaryotic pathogens

Question 8

Neutrophils

Answer 8

Neutrophils – 55-90% - lobed nuclei with lavender granules; phagocytes

Question 9

Macrophages

Answer 9

Monocytes, macrophages – 3-7% - largest of WBCs, kidney-shaped nucleus; phagocytic

Macrophages: final differentiation of monocytes

Question 10

Lymphocytes

Answer 10

Lymphocytes – 20-35%, specific immune response

Question 11

Basophils

Answer 11

Basophils – 0.5% - constricted nuclei, dark blue granules; release potent chemical mediators

Question 12

Plasma cells

Answer 12

Whole blood: plasma and formed elements (blood cells)
• 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 13

B and T lymphocytes

Answer 13

B (humoral immunity): activated B cells produce
antibodies

T cells (cell-mediated immunity): activated T cells 
modulate immune functions and kill foreign cells

Question 14

Signs and symptoms of inflammation

Answer 14

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

Pyrogen and fever

Answer 15

Fever is initiated by circulating pyrogens which reset the hypothalamus to increase body temperature; signals muscles to increase heat production and vasoconstriction

Question 16

Components of specificity and memory of acquired immunity

Answer 16

Unlike the innate immune system, the adaptive immune system relies on fewer types of cells to carry out its tasks: B cells and T cells. Both B cells and T cells are lymphocytes that are derived from specific types of stem cells, called multipotent hematopoietic stem cells, in the bone marrow.

Question 17

Agglutination

Answer 17

Ab aggregation; cross-linking cells or particles into large clumps

Question 18

Opsonization

Answer 18

Process of coating microorganisms or other particles with specific antibodies so they are more readily recognized by phagocytes. Carried out by antibodies called “opsonins”

Question 19

Neutralization

Answer 19

Antibodies fill the surface receptors on a virus or the active site on a microbial enzyme to prevent it from attaching

Question 20

Complement Fixation

Answer 20

Activation of the classical complement pathway can result in the specific rupturing of cells and some viruses

Question 21

Anamnestic response

Answer 21

renewed rapid production of an antibody following second or later contact with the provoking antigen or with related antigens.

Question 22

Monoclonal antibodies

Answer 22

Originate from a single clone and have a single specificity for antigen

Pure preparation of antibody

Single specificity antibodies formed by fusing a mouse B cell with a cancer cell

Used in diagnosis of disease, identification of microbes and therapy

Question 23

Artificial, natural, active, passive immunizations

Answer 23

Active immunity – results when a person is challenged with antigen that stimulates production of antibodies; creates memory, takes time, and is lasting

Passive immunity – preformed antibodies are donated to an individual; does not create memory, acts immediately, and is short term

Natural immunity – acquired as part of normal life experiences

Artificial immunity – acquired through a medical procedure such as a vaccine

Question 24

Precipitation

Answer 24

Aggregation of particulate antigen