Exam 1: Innate Immunity

Question 1

2 types of immune responses

Answer 1

Innate Immune Response

Adaptive Immune Response

Question 2

What is innate immuniy

Answer 2

Natural or native immunity

Present from birth

Protect organism from injury or infection without prior contact

Question 3

What is complement

Answer 3

Group of proteins that produce holes/opening (damage) on cell membrane of bacteria

Question 4

Phases of initial response to infection: Innate immunity (3)

Answer 4

1. Infection
2. Recognition by performed, non-specific and broadly specific effectors
3. Removal of infectious agent

Question 5

Phases of initial response to infection: Early induced innate response (4)

Answer 5

1. Infection
2. Recognition of microbial-associated molecular patterns (MAMPs)
3. Inflammation recruitment and activation of effector cells
4. Removal of infectious agent

Question 6

Phases of initial response to infection: Adaptive immune response (5)

Answer 6

1. Infection
2. Transport of antigen to lymphoid organs
3. Recognition by naïve B and T cells
4. Clonal expansion and differentiation to effector cells
5. Removal of infectious agent

Question 7

Innate immunity - Components: physical barriers

Answer 7

Mechanical factors, chemical factors, microbiological factors

Question 8

Physical barriers: Mechanical factors

Answer 8

Skin and hair coat

Ciliary movement in epithelium of respiratory tract

Peristaltic movement in intestinal tract - like diarrhea

Washing effect by tears and saliva

Dense mucus layer in vagina, digestive tract, and respiratory tract - very viscous so traps pathogens

Question 9

Physical barriers: Chemical factors

Answer 9

Fatty acids, mainly in sweat - inhibit growth of bacteria

Lysozyme and phospholipase in tears, saliva, nasal
secretions - inhibit growth of infectious agents

Low pH of sweat and gastric juices - antibacterial effects

Surfactants like opsonins in lungs - enhance phagocytosis

Question 10

Physical barriers: Microbiological factors

Answer 10

Normal biota on skin and digestive tract - prevents infection by secreting inhibitory substances that inhibit colonization and growth of infectious microorganisms

Question 11

Secretions

Answer 11

Gastric mucosa secretes HCl –> pH 2 or less

Bile and pancreas secrete numerous detergents

Physical flushing of milk, saliva, tears, urine removes microorganisms

Question 12

Secretions from epithelial and endothelial cells - skin

Answer 12

Sebaceous glands - sebum –> water repellant and acidic

Question 13

Commensal organisms

Answer 13

Normal bacteria present in animal

In digestive tract, respiratory tract, reproductive tract, and skin

Do not produce disease

Compete with pathogens for nutrients and space

Have an influence on intestine development and adaptive immune response

Question 14

Innate Immune Response (4)

Answer 14

First line of defense

Not specific

Immediate

No memory

Question 15

Adaptive Immune Response (4)

Answer 15

Second line of defense

Specific

Delayed in time

Leaves memory

Question 16

Innate immunity - Components: Humoral barriers

Answer 16

Complement system, antibacterial enzymes

Question 17

Innate immunity - Components: cellular barriers

Answer 17

Phagocytic system, NK cells

Question 18

Innate immunity - Components: Commensal organisms

Answer 18

Commensal organisms - normal flora

Question 19

Secretions from epithelial and endothelial cells - lysozymes

Answer 19

Antimicrobial protein –> tears, saliva, milk, mucus of intestine

Question 20

Secretions from epithelial and endothelial cells - defensins and cathelicidins

Answer 20

Positive charged proteins that insert into negative charged microbial membranes and punch holes in them

Question 21

Secretions from epithelial and endothelial cells - Lactoferrin

Answer 21

Found in milk and sequesters iron –> makes iron unavailable for bacterial growth

Question 22

Secretions from epithelial and endothelial cells - Lactoperoxidase

Answer 22

Generates reactive oxygen compounds –> damage microbes