Lecture 8- Innate Immunity

Question 1

what does the immune system do?

Answer 1

fights off foreign material that threatens the body and protects against disease

Question 2

what are the two different types of immunity?

Answer 2

innate
adaptive

Question 3

what is adaptive immunity?

Answer 3

highly specific

Question 4

what is innate immunity?

Answer 4

non- specific

Question 5

what does the innate immune system specifically do?

Answer 5

protects humans from most infectious diseases

Question 6

when does immunity start?

Answer 6

at birth and is always present

Question 7

what is natural host resistance?

Answer 7

host resistance has no memory but our susceptibility to pathogens varies from one species to another

Question 8

what is an example of how susceptibility to pathogens varies from one species to another?

Answer 8

HIV can infect human cells but not mice
anthrax causes fatal blood infection in cattle but just a minor skin infection in humans

Question 9

can the immune system be specific?

Answer 9

YES can be specific for a particular tissue

Question 10

can pathogens be specific?

Answer 10

yes! they prefer a specific body site to initiate infection (some have specific receptors and bind to specific cell types)

Question 11

how can pathogens spread?

Answer 11

aerosols (sneezing)
bodily fluids (blood)

Question 12

what is Clostridium tetani?

Answer 12

anaerobic and thus prefer to live in our anaerobic bodies, can be ingested or can enter into deep wounds. this is why we get tetanus shot to prevent microbes like this

Question 13

how does the innate immune system protect us? what barriers/ defenses does it have? (5)

Answer 13

physical barriers
chemical defenses
cellular defenses
molecular defenses
physiological processes

Question 14

what are two main barriers to infection?

Answer 14

skin
mucous membranes

Question 15

how does the skin act as a physical barrier?

Answer 15

prevents invasion by microbes because its slightly acidic (pH 5) which microbes dont like
high NaCl (because salty microbes dont like this)

Question 16

what is the skin made of?

Answer 16

keratin which is a tough protective protein

Question 17

what can grow on the skin and how?

Answer 17

fungal infections can grow on skin surface can break skin to get in but many require broken skin in order to penetrate and cause infection

Question 18

what is mucous produced by?

Answer 18

goblet cells which trap microbes preventing infection

Question 19

what does a mucous membrane do?

Answer 19

line tracts in the body and contain antimicrobial secretions

Question 20

what tracts does the mucous membrane line? 4

Answer 20

respiratory tract
gastrointestinal tract
large intestine (colon)
genitourinary tract

Question 21

what does the respiratory tract contain?

Answer 21

mucociliary escalator

Question 22

what do the mucosal epithelial cells within the respiratory tract contain?

Answer 22

cilia

Question 23

what do cilia do in the respiratory tract?

Answer 23

filter incoming air through a sweeping action
the sweeping action allows for removal of mucous and trapped microbes from the lungs

Question 24

what are the two major components of the gastrointestinal tract?

Answer 24

stomach
small intestine

Question 25

do many microbes survive in the stomach? why?

Answer 25

no because its a very acidic environment (pH 2) and contains proteases

Question 26

how does the small intestinal tract counteract the high pH of the stomach?

Answer 26

pancreatic juice that contains pancreatic enzymes buffers acidity of incoming contents from the stomach (pH 7)

Question 27

do many microbes live in the small intestine?

Answer 27

no, the microbes cant maintain cellular integrity in the harsh environment with the bile

Question 28

what does the large intestine contain?

Answer 28

normal microbiota

Question 29

where does a normal microbial resident that lives in the large intestine live symbiotically?

Answer 29

inside the colon

Question 30

how do microbes living in the large intestine and colon persist?

Answer 30

by using attachment sites

Question 31

what does it mean to consume undigested nutrients in the large intestine?

Answer 31

competitive exclusion

Question 32

what does it mean to produce antimicrobial compounds in the large intestine?

Answer 32

microbial antagonism