Chapter 16: Host-Microbe Interactions: Principles of Disease + Microbiota

Question 1

What is pathology?

Answer 1

the study of disease

Question 2

What is etiology?

Answer 2

cause of the disease

Question 3

what is pathogenesis?

Answer 3

• how the disease develops

Question 4

What is a pathogen?

Answer 4

• organism that can cause disease

Question 5

What is pathogenicity?

Answer 5

ability to cause disease

Question 6

What is virulence?

Answer 6

• ability to cause harm (severity of disease)

Question 7

What is infection?

Answer 7

growth of pathogens in the body

Question 8

what is disease?

Answer 8

an abnormal state where the body is not capable of performing normal functions

Question 9

How many human cells does a typical human body have?

Answer 9

1 x 10^13 human cells

Question 10

How much bacteria does a typical human body have?

Answer 10

1 x 10^14 bacteria

Question 11

The normal microbiota are _____ residents in the human body

Answer 11

permanent

Question 12

The transient microbiota are __ permanent residents. How long can they be present for?

Answer 12

• not
• days, weeks, months

Question 13

Where can you find microbiota? (like localization) (2)

Answer 13

• localized to certain parts of the body
• generally exposed areas
  ex. skin, respiratory, intestinal, urinary tracts

Question 14

Do internal tissues like blood, muscle, brain, etc. have microbes?

Answer 14

• they are normally free from microbes

Question 15

What is the role of microbiota?

Answer 15

• benefit the host by preventing growth of pathogens

Question 16

What is microbial antagonism?

Answer 16

• members of the microbiota produce substances harmful to invading microbes

Question 17

What is competitive exclusion?

Answer 17

• microbiota use up available nutrients, preventing growth of pathogens

Question 18

What is an example of a bacteria that uses the competitive exclusion principle? (4)

Answer 18

• clostridium difficile
• inhibited by normal microbiota of the large intestine
• if the normal microbiota is eliminated (antibiotic treatments), C. difficile can cause infection
• leads to fatal inflammation of the colon

Question 19

What are the benefits of the microbiota? (2)

Answer 19

• some bacteria produce enzymes that aid digestion
• E. Coli in the large intestine makes vitamin K and B