Fundamentals of Host Defenses

Question 1

immunity

Answer 1

ability of a host to resist infection or disease

Question 2

immunology

Answer 2

study of immune responses

Question 3

innate immunity

Answer 3

built in ability of the immune system to target pathogens

Question 4

adaptive immunity

Answer 4

ability of immune system to target a particular pathogen

Question 5

Innate Immunity: Barrier

skin

Answer 5

largest organ, mechanical barrier

Question 6

Innate Immunity: Barrier

epidermis

Answer 6

outer layer compsed of tightly packed keratinocytes
- move to top layer in. about 14 days

Question 7

Innate Immunity: Barrier

stratum corneum

Answer 7

top layer, 15-20 layers of thick, dead cells, embedded in lipid matrix that is acidic

Question 8

Innate Immunity: Barrier

dermis

Answer 8

connective tissue, sweat glands, hair follicles

Question 9

Innate Immunity: Barrier

sebum

Answer 9

produced by sebaceous glands, rich in fatty acids

Question 10

Innate Immunity: Barrier

sweat

Answer 10

produced by sweat glands, makes skin hypertonic to microbial cell cytoplasm

Question 11

Innate Immunity: Barrier

langerhan cells

Answer 11

immune cells

Question 12

Innate Immunity: Barrier

mucous membrances (mucosa)

Answer 12

epithelial cells and specialized cells that act as a barrier and trap pathogens

Question 13

Innate Immunity: Barrier

goblet cells

Answer 13

produce mucus which includes glycoproteins, proteoglycans, lipids, proteins, and DNA which trap foreign materials

Question 14

Innate Immunity: Barrier

paneth cells

Answer 14

secrete antimicrobial peptides and enzymes

Question 15

Innate Immunity: Barrier

mucociliary escalator

Answer 15

coats surfaces of the lower respiratory tract, cilia ‘wave’ to move particles up

Question 16

Innate Immunity: Barrier

peristalsis

Answer 16

columnar epithelial cells of the GI tract are shed to reduce attached microbes

Question 17

Communication in the immune system

cytokines

Answer 17

generic term for soluble, low weight proteins or glycoproteins that serve as intercellular signaling molecules

Question 18

Communication in the immune system

JAK-STAT

Answer 18

• signal transduction pathway
• phosphorylation of Janus Kinase

Question 19

Host micrbiome

holobionts

Answer 19

host and its microbes who have evolved together and form a single functional unti

Question 20

Host micrbiome

microbial antagonism/bacterial interference

Answer 20

adaptations in which one microbe inhibits the growth or kills a competing microbe

Question 21

Host micrbiome

virome

Answer 21

entire population of viruses within a particular host

Question 22

Host micrbiome

gut-brain axis

Answer 22

metabolites produced by the microbiome impact behavior

Question 23

Cells of the immune system

leukocytes

Answer 23

white blood cells

Question 24

Cells of the immune system

granulocytes

Answer 24

contain cytoplasmic inclusions which contain toxins or enzymes that are visible on stained blood smears

Question 25

Cells of the immune system: granulocytes

mast cells and basophils (<1% of WBCs)

Answer 25

• not phagocytic
• associated with allergies
• undergo degranulation

Question 26

Cells of the immune system: granulocytes

degranulation

Answer 26

release of vasoactive mediators which influence blood vessels and the inflammatory response

Question 27

Cells of the immune system: granulocytes

eosinophils (2-4% of WBCs)

Answer 27

• weak phagocytes
• secrete cytotoxic enzymes that target larger, extracellular pathogen

Question 28

Cells of the immune system: granulocytes

neutrophils (50-65% of WBCs)

Answer 28

• highly phagocytic
• highly motile
• circulate in blood and migrate to infected tissues
• NETs (neutrophil extracellular traps) of DNA can trap extracellular pathogens

Question 29

Cells of the immune system: monocytes

macrophages (2-9% of WBCs are monocytes)

Answer 29

monocytes develop from myeloid precursor and develop into macrophages in the blood

Question 30

Cells of the immune system: monocytes

dendritic cells

Answer 30

have vast surface area due to cellular projections

Question 31

Cells of the immune system: lymphoid cells

innate lymphoid cells

Answer 31

include NKs and other lymphoid precursor derived cells involved in innate immunity
- aid in lymph development
- activate macrophage
- trigger vasodilation, mucus secretion, release antimicrobial peptides

Question 32

Cells of the immune system: lymphoid cells

Natural Killer cells

Answer 32

• detect kill or don’t kill signals from host cells
• stimulate apoptosis in cells determined to be stressed, malignant, or virally infect

Question 33

Cells of the immune system: lymphoid cells

T cells

Answer 33

recognize antigens displayed on host cells via glycoproteins called the MHC

Question 34

t cell receptors

Answer 34

bind to antigens specific to a particular pathogen and stimulatet t cell activation and cytokine production

Question 35

Cells of the immune system: lymphoid cells

B cells

Answer 35

produce antibodies that neutralize and/or tag antigens for destruction

Question 36

Organs and tissues of the immune system

primary organs and tissues

Answer 36

where HSCs differentiate into immune cells

Question 37

Organs and tissues of the immune system: primary

bone marrow

Answer 37

site of b cell development and selection during which self-reactive B cells are eliminated