Innate Immunity

Question 1

What’s cells are involved in innate immunity ?

Answer 1

Macrophages
Neutrophils
Dendritic cells
Natural killer cells

Question 2

What are the physical barriers in innate immunity ?

Answer 2

Repository tract
Skin
Eyes
Genitourinary tract
GI tract

Question 3

What defenses do we have at the these barriers ?

Answer 3

Skin - Tight epithelial layers , Fatty acids.
All epithelium - defensins.
Respiratory - enzymes, flow of air or fluid.
GI tract - ciliated cells, low PH , normal microbiota.

Question 4

How do white blood cells recognize pathogens or damage ?

Answer 4

Through damps ( damage associated) and pamps (pathogen associated) .

Question 5

What’ types of pattern recognition are there ?

Answer 5

Nod receptors
Toll-like receptors
RIG- like receptors

Question 6

What are the types of pro inflammatory cytokines?

Answer 6

Interleukin-1 beta
Interleukin-6
Tumor necrosis factor alpha

Question 7

What do pro- inflammatory cytokines do ?

Answer 7

Activate the endothelium.
Increase permeability of the vascular endothelium.

Question 8

What protein makes cells produce pro inflammatory cytokines ?

Answer 8

NFKB

Question 9

What receptors cause phagocytosis?

Answer 9

Phagocytic receptors on phagocytes

Question 10

What cells are phagocytes ?

Answer 10

Macrophage
Neutrophil
Dendritic
B cells

Question 11

What are the main signs of inflammation ?

Answer 11

Swelling
Redness
Heat
Pain

Question 12

How do macrophages kill the pathogen ?

Answer 12

They induce phagocytosis so the pathogen is in a phagosome it emerges with a lysosome, and makes phagolytosome. In this they have got digestive enzymes with break down the pathogen.

Question 13

What does the c3b compliment protein do ?

Answer 13

Binds to pathogens and makes them more visible to phagocytes.

Question 14

What do c5a and c3a compliment proteins do?

Answer 14

They induce chemotaxis.

Question 15

What is chemotaxis ?

Answer 15

It’s a process by which the immune system recruits more white blood cells.

Question 16

What are chemokines ?

Answer 16

Proteins that attract white blood cells to the site of infection.

Question 17

What are the effects of the interferons ?

Answer 17

Induce chemokine to recruit lymphocytes.
Activate natural killer cells.
Activate dendritic cell and macrophages.

Question 18

What are the MHC molecules ?

Answer 18

MHCI and MHCII

Question 19

What’s the function of MHCI?

Answer 19

Present peptide antigens to pathogen specific cytokines T cells.

Question 20

What’s the natural killer cells?

Answer 20

Have receptors to identify when a cell is infected with a pathogen.
Contains granules which can kill cells and produce interferon gamma.

Question 21

What is the natural killer cells and its function ?

Answer 21

Type of white blood cell that destroys infected and diseased cell.
A type of lymphocyte like B/T cells.
They destroy harmful cells in early stages preventing viruses from spreading.

Question 22

What granules are present in natural killer cells ?

Answer 22

Perforin and granzyme

Question 23

What determines the differentiation of helper T cells ?

Answer 23

Polarising cytokines released by antigen presenting cells.

Question 24

Which antigen do CD8 cells recognize ?

Answer 24

Angiogenesis on MCH I

Question 25

What antigen do CD4 T cells recognize?

Answer 25

Antigen on MHC II

Question 26

What is T cell energy?

Answer 26

If an antigen presenting cell phagocytoses self molecules and presents them to T cell, the antigen presenting cell won’t be expressing co stimulatory molecules which puts the T cell in an anergic (unresponsive) irreversible state.

Question 27

What do natural killer cells do?

Answer 27

They recognize infected cells through their altered or lack of MHC I expression and trigger cell apoptosis by releasing granules containing granzymes and perforin

Question 28

Who doe Nodal cells generate action potential ?

Answer 28

Nodal cells contain HCN na+ channels which open at around -60mv and then T type ca channels which open around -55mv, decaying the nodal cells pacemaker potential until they reach threshold at -40mv. L-type ca channels then open at threshold potential and ca flows in depolarizing the cell.

Question 29

How do nodal cell propagate action potential to the myocardium?

Answer 29

Nodal cells contain gap junctions (connexon proteins) and adhesive proteins( desmosomes) (Gap junctions + desmosomes = intercalated discs)

Question 30

What do desmosomes proteins and connexons do ?

Answer 30

Desmosomes proteins keep nodal cells and myoctes adhere, whereas connexons allow ions to flow between cells down their electrochemical gradient to propagate the action potential.

Question 31

How does the heart generate electrical impulses?

Answer 31

The heart nodal cells and myoctyes which exhibit automatically (intrinsic conduction) and self ternate action potentials spontaneously without extrinsic influence.

Question 32

What does the term functional syncytium mean ?

Answer 32

It refers to the organized propagation of action potentials for nodal cell to myocyte and myoctye to myocyte - producing an organized simultaneous contraction of the cardiac muscle which acts as a pump.