Topic P. Host Immune Responses

Question 1

what are the two main type of host defenses?

Answer 1

1. innate (non-specific) and adaptive (specific) immunity

Question 2

What are the components of innate immunity?

Answer 2

1. barriers (physical, chemical, microbiological)
2. white blood cells
3. inflammation
4. fever
5. antimicrobial substances

Question 3

What are the components of adaptive immunity?

Answer 3

1. b cell antibody production
2. t cell activation of immune cells

Question 4

What are microbe-associated molecular patterns (MAMPs)

Answer 4

unique molecular structures on microbes that the immune system recognizes, heling distinguish microbes from human cells

Question 5

What are examples of MAMPs on different microorganisms?

Answer 5

• protozoa: specific surface of glycoproteins
• virus: viral capsule
• bacteria - peptidoglycan
• yeast: polysaccharides in cell walls

Question 6

What are the key steps in phagocytosis?

Answer 6

1. chemotaxis
2. adherence
3. engulfment
4. phagosome formation
5. fusion with lysosome
6. digestion/killing
7. release of debris

Question 7

What are the functions and characteristics of neutrophils?

Answer 7

1. first responders
2. short-lived
3. phagocytic
4. primarily antibacterial and antifungal
5. major component of pus

Question 8

What are the functions and characteristics of macrophages?

Answer 8

1. long-lived
2. derived from monocytes
3. phagocytic
4. engulf viruses, bacteria, and debris
5. release inflammatory signals
6. help activate adaptive immune cells

Question 9

What are the main functions of B cells?

Answer 9

1. produce antibodies (humoral immunity)
2. form plasma cells and memory b cells

Question 10

What are the main functions of T cells?

Answer 10

1. kill infected host cells (cytotoxic T cells)
2. activate b cells, macrophages, and other T cells (helper T cells)

Question 11

How do B and T cell receptors differ?

Answer 11

• b cells have membrane-bound receptors that can be secreted as antibodies
• t cells have receptors embedded in the membrane that are never secreted

Question 12

What is clonal deletion?

Answer 12

the process where b and t cells that recognize self-antigens are destroyed before they leave the bone marrow or thymus to prevent autoimmunity

Question 13

What is clonal selection?

Answer 13

the process where lymphocytes with receptors for specific non-self antigens are activated, proliferate, and differentiate into effector and memory cells