Class 5 - Innate Immunity

Question 1

List examples of the body’s first line of defense in innate immunity

Answer 1

skin, mucous membranes, bodily fluids

Question 2

List examples of the body’s second line of defense in innate immunity

Answer 2

internal antimicrobial substances,
NK cells,
phagocytes,
inflammation,
fever

Question 3

Name of the immune-functioning enzymes found in the lacrimal (tears) and salivary (saliva) gland secretions…

Answer 3

lysozymes (destroys microoganisms)

Question 4

What are the 4 types of internal antimicrobial substances?

Answer 4

interferons
complement system
ion-binding proteins
antimicrobial peptides

Question 5

Where do interferons come from? What do they do?

Answer 5

proteins secreted by lymphocytes, macrophages, fibroblasts that have been infected by a virus

they induce antiviral protein production to stop viral replication

Question 6

What are 3 functions of the complement system?

Answer 6

cause microbe cytolysis
promote phagocytosis
contribute to inflammation

Question 7

Give examples of iron-binding proteins and where they are found

Answer 7

transferrin (blood, tissue fluids)
lactoferrin (milk, saliva, mucous)
ferritin (liver, spleen, bone marrow)
hemoglobin (RBCs)

Question 8

Which type of internal antimicrobial substance do microbes not develop resistance to?

Answer 8

AMPs (antimicrobial peptides) - broad spectrum antibiotic effects (attract dendritic and mast cells)

Question 9

What are some examples of AMPs in the body?

Answer 9

dermacidin (sweat glands)
defensins + cathelicidins (neutrophils, macrophages, epithelia)
thrombocidin (platelets)

Question 10

What do NK cells attack?

Answer 10

any abnormal or unusual cell of the body/foreign cells

Question 11

Where are NK cells found?

Answer 11

in the blood (5-10% of lymphocytes)

spleen
lymph nodes
red bone marrow

Question 12

Explain antibody dependent cell-mediated cytotoxicity

Answer 12

NK cells bind to the target cell via an antibody for the target cell (antibody dependent.)

They then release two toxic substances, perforin and granzymes, to destroy the target cell (cytotoxicity)

Question 13

What effect does perforin have?

Answer 13

creates channels in membrane of a target cell so the cell swells with ECF and bursts (cytolysis)

Question 14

What effect do granzymes have?

Answer 14

induce apoptosis in target cells (digest proteins)

Question 15

True or false: NK cells destroy infectious microbes

Answer 15

false. NK cells kill the infected cell. the microbe inside is then released, to be destroyed by phagocytes.

Question 16

Histiocytes, alveolar macrophages, microglial cells, and, Kupffer’s cells are all examples of…

Answer 16

fixed macrophages in specific tissues

Question 17

What are the 5 phases of phagocytosis?

Answer 17

1. chemotaxis (migration)
2. adherence
3. ingestion
4. digestion
5. elimination (killing)

Question 18

What is a phagolysosome?

Answer 18

product of the merging of a phagosome and lysosome so the lysosome can digest the contents of the phagosome

Question 19

What attracts macrophages? (chemotaxis)

Answer 19

WBC’s
damaged tissue cells
activated complement proteins
invading microbes

Question 20

What are the 3 basic stages of inflammation?

Answer 20

1. vasodilation/increased permeability
2. emigration of phagocytes + demolition
3. tissue repair/healing

Question 21

What cells release histamine?

Answer 21

basophils
mast cells
platelets

Question 22

What effect does histamine have?

Answer 22

dilation and increased permeability of blood vessels

Question 23

What substance is formed in the blood, is responsible for much of the pain of inflammation, and produce chemotactic stimuli?

Answer 23

kinins

Question 24

What substance intensifies the effects of histamine and kinins, and stimulates migration of phagocytes through capillary walls?

Answer 24

prostaglandins

Question 25

What cells produce leukotrienes?

Answer 25

basophils, mast cells

Question 26

What is the function of leukotrienes?

Answer 26

promote adherence of phagocytes to pathogens

chemotactic stimuli

Question 27

True or false: both neutrophils and the complement system stimulate the release of histamine

Answer 27

true

Question 28

How does fever help fight infection?

Answer 28

intensifies the effects of interferons
inhibits bacterial growth
speeds up repair reactions

Question 29

innate immunity is designed to prevent_____ and ____

Answer 29

microbes from entering

help eliminate those that have gained access

Question 30

adaptive immunity is a specific recognition of microbes once they have….

Answer 30

breach innate defenses (specific responses to specific microbes involving both B and T cells)

Question 31

what does periodic shedding of the skin have to do with innate immunity?

Answer 31

periodic shedding removes bacteria from surface

Question 32

cilia movement of mucous membranes, in the airways helps to do what?

Answer 32

expel trapped micro-organisms and foreign substances