6. Microbiology and intugementary System

Question 1

3 components of host-microbe infection

Answer 1

Host ➡️ environment ➡️ microbe

Question 2

Commensalism

Answer 2

One species lives in or on the body of another

Question 3

Mutualism

Answer 3

Reciprocal benefits for both organisms

Question 4

Parasitism

Answer 4

Only the parasite benifits

Question 5

Fact: host-pathogen interaction does not always result in disease

Answer 5

• many microbes, infection only caused by a few
• pathogens do not cause disease in every host
• non-pathogens cause disease in most hosts

Question 6

What is needed to initiate infection

Answer 6

Exposure ➡️ adherence ➡️ invasion ➡️ infection

Further exposure (leading to tissue damage):
➡️Toxicity (toxin effects are local or systemic)
➡️invasiveness (further gross at original and distance sites)

Question 7

Chain of infection

Answer 7

1. Infectious agent
2. Reservoir
3. Portals of exit
4. Modes of transmission (physical, contact, droplet, airborne)
5. Portals of entry
6. Susceptible host

Question 8

Living infectious agents

Answer 8

Prokaryotes - bacteria

Eukaryotes - fungi & parasites

Question 9

Non-living infectious agents

Answer 9

Viruses and prions

Question 10

Prokaryotes

Answer 10

Bacteria. Has a cell wall with no membrane-bound organelles

Question 11

Fungi (plant-like)

Answer 11

• Closest relative to humans
• single called (yeast)
• multi-called (mounds/filamentous fungi)
• common features: membrane-bound nucleus and organelles, heterotrophic - enzyme diversity

Question 12

Protozoans

Answer 12

• Single-called eukaryote with various sub cellular organelles and outer membrane w/o cell wall.
• free-living parasites
• can be classified by their locomotor organelles: amoeba, flagellates, ciliates, sporozoa (non-moving)

Question 13

Helminths: flatworms

Answer 13

Tape worms (cestodes)
Flukes (trematodes)

Question 14

Helminths - Round Worms

Answer 14

Pinworms, hookworms (nematodes)

Question 15

What viruses are comprised of

Answer 15

Nuclei acid
Capsid (protein coat)
+/- envelope (lipid)

Question 16

How viruses obligate intracellular parasites

Answer 16

• Replicate within host cell
• Lack enzymes required for replication and protein synthesis
• specious specific

Question 17

Prions

Answer 17

Abnormal forms of normal cellular proteins:

• misfolded protein (prion) accumulates in cells disrupting normal functions
• prion protein triggers misfolding of normal proteins = prion replication

Question 18

How do prions emerge?

Answer 18

Sporadic
Inherited
Acquired (transmission or consumption)

Question 19

Reservoirs

Answer 19

Where microbes persist:

• human
• animal
• non-living (water, soil & biofilms)

Question 20

Portals of entry and exit

Answer 20

Endogenous: opportunistic pathogens derived from normal regional flora
Exogenous: Pathogens derived from the external environment

Pathogens must gain access to a specific anatomical niche to initiate infection (tropisms)

Question 21

Vehicle transmission

Answer 21

Airborne
Waterborne
Foodborne

Question 22

Vector transmission

Answer 22

Mechanical or biological