Chapter 15- Pathogencity

Question 0

most common path of entry

Answer 0

respiratory tract, 2nd most common is the gastrointestinal tract

Question 1

pathway of infection

Answer 1

1. enter host
2. penetrate host defense
3. damage to host cells
4. exit host

Question 2

tracts of entry

Answer 2

• mucous membranes (respiratory tract, GI tract, genitourinary, conjuctiva (eyes))
• skin (hair follicles, sweat glands, broken skin)

Question 3

ID50

Answer 3

the dose of a microbe that is infectious for 50% of the population

Question 4

adherence

Answer 4

microbes must attach to host (either use ligands/receptors on our cells or their biofilm)

Question 5

capsules (penetration of host defense)

Answer 5

resist immune defense

Question 6

cell wall (penetration of host defense)

Answer 6

certain proteins and lipids resist immune response

Question 7

antigenic variation

Answer 7

surface antigens become unaffected by antibodies

Question 8

ways of damaging host cells

Answer 8

use of host’s nutrients, direct damage (cell lysis, use nutrients, produce waste) toxins (poisonous substances made by the virus)

Question 9

exotoxins

Answer 9

bacteria secretes toxin into medium

Question 10

endotoxin

Answer 10

part of the bacteria’s cell wall

Question 11

portals of exit

Answer 11

most use same portal of entry, respiratory and GI tract, genitourinary tract, skin or wounds

Question 12

endotoxic shock

Answer 12

macrophages release TNF (a type of cytokine), increase blood capillary permeability, lose fluid, drop in blood pressure