Module 4 L5

Question 1

Skin characteristics

Answer 1

dense keratinized layer, low ph 5.5, fatty acids inhibit microbial growth

Question 2

Common routes of infection

Answer 2

respiratory, intestinal, urogenital

Question 3

Bacteria breaks defenses by

Answer 3

releasing enterotoxins, invade and damage internal mucosa

Question 4

virus breaks defenses by

Answer 4

nonenveloped ones are resistant to bile and digestive enzymes

Question 5

Fungi break defenses by

Answer 5

in immunocompromised hosts

Question 6

Intestinal protozoan break defenses by

Answer 6

relying on cysts for transmission

Question 7

intestinal helminthes break defenses by

Answer 7

causing obstruction of the gut

Question 8

How pathogens are disseminated

Answer 8

vertical transmission - HBV, CMV, treponema pallidum

Question 9

4 mechanisms microbes evade immune defense

Answer 9

remain inaccessible, change antigenic repertoires, inactivate antibodies or complement resisting phagocytosis, suppress host adaptive immune esponse

Question 10

Intestinal tract defenses

Answer 10

acidic gastric ph, mucus, pancreatic enzymes, bile detergents, defensins, IgA, normal gut flora

Question 11

Urogenital tract defenses

Answer 11

frequent urination, low pH in vagina from catabolism of glycogen in normal epithelium by commensal lactobacilli

Question 12

How pathogens break defenses in urogenital tract

Answer 12

antibiotics kill lactobacilli and make vagina susceptible to infection

Question 13

Changing antigenic repertoires

Answer 13

flu, rhinovirus cold, HIV

Question 14

HIV viral entry

Answer 14

gp120 binds to CD4 and to CXCR4 or CCR5

Question 15

Rhinovirus viral entry

Answer 15

bind to ICAM-1

Question 16

SarsCOV2 viral entry

Answer 16

spike protein/ACE2 receptor

Question 17

Virus encoding proteins that inhibit apoptosis

Answer 17

homogloues of the cellular BCL-2

Question 18

Major component of cell wall gram negative bacteria

Answer 18

Bacterial endotoxin lipopolysaccharide

Question 19

Diptheria inhibits protein synthesis by

Answer 19

disulfide bind reduced and broken into the cytoplasm releasing amino fragment A catalyzing transfer of ADP from NAD to EF2 and inactivates it

Question 20

1 toxin molecule can kill a cell by ADP

Answer 20

ribosylating more than 10^6 molecules