Chapter 26: Innate Immunity

Question 1

immunity

Answer 1

ability of organism to resist infection

Question 2

innate immunity

Answer 2

built-in capacity of immune system of multicellular organisms to target pathogens that are seeking to colonize the host
does not require previous exposure to a pathogen

Question 3

adaptive immunity

Answer 3

acquired ability to recognize and destroy a particular pathogen
dependent on previous exposure
directed toward individual molecular component of pathogen- antigen

Question 4

natural host resistance

Answer 4

normal microbiota helps resist pathogens on skin and in gut

Question 5

competitive exclusion

Answer 5

harmless microbes limit available nutrients and sites for infection

Question 6

white blood cells

Answer 6

make up 0.1% of cells in blood
aka leukocytes (buff coat)
include lymphocytes, granulocytes, monocytes

Question 7

lymphocytes

Answer 7

specialized leukocytes involved in adaptive immunity
B cells: originate and mature in bone marrow, produce antibodies
T cells: originate in bone marrow, mature in thymus, produce T cell receptors

Question 8

Antigen-presenting cells

Answer 8

engulf, process, and present antigens to lymphocytes, monocytes, macrophages, dendritic cells

Question 9

granulocytes

Answer 9

contains toxins or enzymes that are released to kill target cells
consist of neutrophils, basophils, eosinophils

Question 10

microbial invasion

Answer 10

ability of a pathogen to enter host cells or tissues, multiply, spread, cause disease

Question 11

cytokines

Answer 11

released by leukocytes and damaged cells
allow communication between WBCs
draws macrophages and neutrophils
large and diverse group of pro or anti inflammatory factors
genetic function is to induce cell migration

Question 12

pathogen associated molecular patterns

Answer 12

pathogens have structures and molecules not found on host cells
ex. LPS common to all gram-neg bacterial outer membranes

Question 13

Toll-like receptors (TLR)

Answer 13

send a signal to nucleus when encounterig a PAMP

Question 14

phagocytes

Answer 14

engulf pathogens upon recognition of PAMPS by their TLRs
some pathogens can survive
some pathogens form capsule

Question 15

inflammation

Answer 15

isolates and limites tissue damage, destroy damaged cells and pathogens
also inadverdently cause damage to healthy tissue in key organs

Question 16

fever

Answer 16

caused by cytokines called pyrogens
increases circulation rates, allows WBCs to get to site of infection
some pathogens cannot tolerate healt
increase in transferrins which sequester iron, limiting pathogen growth

Question 17

systemic inflammation

Answer 17

can lead to shock because of decreased blood pressure
gram neg bacteria contain LPS, triggers proinflammatory response –> cytokine storm which can be fatal
ex. salmonella or e. coli

Question 18

signs of inflammation

Answer 18

widening of capillaries: increase vascular permeability
more blood flow: redness, pressure
water enters tissue (swelling): flush debris to lymphatic system, local pain
fever

Question 19

genes induced by PAMP and TLRs

Answer 19

1. cytokine production: attract immune cells
2. phagocytosis: kill pathogen
3. communication with adaptive immune cells: antigens
4. inflammation: interleukins
5. tissue healing

Question 20

complement system activation

Answer 20

direct attack, recruitment of phagocytes, opsonization

Question 21

opsonization

Answer 21

making a target easier to phagocytose

Question 22

complement system

Answer 22

set of circulating inactive proteins tjay are activated in response to a pathogen

Question 23

major histocompatibility complexes (MHC)

Answer 23

present small fragments of protein
every cell in body presents every protein it creates
inform immune system what is/isn’t foreign
natural killer cells kill everything w/o MHC
many viruses force body cells to decrease/stop expression of MHC

Question 24

natural killer (NK) cells

Answer 24

cytotoxic lymphotcytes
recognize and kill cells that do not display MHC and have stress proteins: likely old, virally infected, cancer…)

Question 25

granzyme

Answer 25

enzyme that induces apoptosis

Question 26

interferons

Answer 26

small cytokine proteins produced by virally infected cells
serve as warning system, prevent viral replication by stimulating production of antiviral protein in uninfected cells once they receive signal from infected cell
infected cell induces apoptosis

Question 27

MHC I

Answer 27

on every cell
present self-protein “I belong to the body”

Question 28

MHC II

Answer 28

present antigens “I found this foreign thing”
only on special immune cells: phagocytes and B cells

Question 29

perforin

Answer 29

pokes holes (perforates) target membrane