#34 Innate Immunity

Question 1

Functions of the immune system

Answer 1

defend against invading pathogens (virus and bacteria)

Remove worn out cells and damaged tissue

identify and destroy mutant cells originating from self

can mount inappropriate response that leads to allergies or autoimmune disease

Question 2

5 types of leukocytes

Answer 2

neutrophils, eosinophils, basophils, monocytes, lymphocytes

Question 3

neutrophil function

Answer 3

phagocytosis

Question 4

eosinophil function

Answer 4

parasite destruction and allergic reactions

Question 5

basophils

Answer 5

histamine and heparin release, allergic reactions

Question 6

monocytes

Answer 6

transform into macrophages, phagocytosis

Question 7

lymphocytes (b and t)

Answer 7

b: secrete antibodies

T: destroy virus infected or mutant cells

Question 8

innate immunity

Answer 8

nonspecific. nonselectively defends against foreign invaders. Rapid but limited responses

Question 9

adaptive immunity

Answer 9

organism adapts to defend against specific invaders for long-term protection

Question 10

innate immunity: how to kill

Answer 10

inflammation, interferon, natural killer cells, complement system

Question 11

goal of inflammation

Answer 11

bring phagocytic cells, fluid, and proteins to the area in order to kill microorganisms, remove debris, prep for healing

Question 12

5 steps of immune response

Answer 12

1. activation of macrophages leads to phagocytosis, cytokines
2. Histamine released from mast cells leads to vasodilation
3. increased capilary permeability bc of histamine leads to edema, pain. clotting
4. Leukocytes migrate to area (monocytes, neutrophils)
5. Phagocytosis of bacteria and debris

Question 13

what are mast cells?

Answer 13

tissue bound basophils

Question 14

what is pus?

Answer 14

leukocytes and digested tissue

Question 15

abcesses

Answer 15

tender, swollen, masses that are often discolored and filled with pus and bacteria

often in armpit, anus, spine, teeth, groin

Question 16

How do immune cells kill bacteria?

Answer 16

When the body detects a foreign bacterial invader, it recruits cells known as neutrophils. These specialized cells generate reactive oxygen species – simply put, they create hydrogen peroxide. In most cases, the hydrogen peroxide will kill the invading bacteria.

Question 17

Explain how and why fever happens after inflammation

Answer 17

When bacteria enters the body it releases exogenous pyrogens. In their attack, immune cells release endogenous pyrogens. Together, these go to the hypothalamus and stimulate prostaglandin release, which increases body temperature

Question 18

How do NSAID’s work?

Answer 18

decrease inflammation by inhibiting production of prostaglandins and histamine ( no phagocyte secretions)

Question 19

how do interferons work?

Answer 19

when infected by viral nucleid acid, cell produces interferon. Travels to other cells and binds, triggers production of enzymes that prevent protein synthesis and break viral RNA so virus can invade, but cannot control the cell.

Question 20

Viral Lytic cycle

Answer 20

virus attaches, injects NA into cell. Host replicates viral DNA/RNA, causing new viruses to be assembled. Host cell eventually lyses and releases all virus particles

Question 21

how do interfereons work? (Cellular mechanism)

Answer 21

bind to surface of cell, signal ISGF3 complex, which binds to gene promoter for anti viral proteins.

Question 22

how are interfereons used in therapy?

Answer 22

inject the inteferon into infected area to prevent the spread of the virus

Question 23

Natural Killer Cells

Answer 23

non-specific, will kill any virus infected or cancer cell. require no antigens, rapidly activated, but few in number

Question 24

complement system

Answer 24

produced by liver, non-specific defense. Complements the action of antibodies. System made up of 9 proteins, normally inactive.

Question 25

2 pathways for activation of complement system

Answer 25

1. Alternate: non-specifiv binding to carbohydrate chains on bacteria
2. Classical: binding to antibodies specific to that bacteria

Question 26

C3 in both pathways (MAC formation)

Answer 26

go signal

Question 27

c5 (MAC complex)

membrane attack complex

Answer 27

goes through cell membrane to recruit c6,7,8,9. MAC is just c5-9.

Question 28

How else can the MAC be activated?

Answer 28

the mannose pathway. Starts with mannose binding lectin

Question 29

what does the complement system do?

Answer 29

chemotaxis (movement of a cell in response to a stimulus), Opsonization (better phagocytosis), activates mast cells, vasodilates, solubilizes things

Question 30

How does the MAC work?

Answer 30

c5-9 form a pore in the membrane causing fluid to rush into the cell and lyse