Cells and Components of the Immune System Flashcards Preview

Term 3: Immunology/Pathology > Cells and Components of the Immune System > Flashcards

Flashcards in Cells and Components of the Immune System Deck (37):
1

Which MHC class is recognized by Cytotoxic T Lymphocytes (CD8+)?

MHC-I

2

Which MHC class is recognized by Helper T Lymphocytes (CD4+)?

MHC-II

3

Do Natural Killer cells recognize MHC presentation?

No, but they recognize the Class I MHC as a "don't kill" signal

4

What do neutrophils do?

phagocytose bacteria coated with IgG and IgM

5

What do Mast Cells and Basophils release upon activation?

-Histamine

-Heparin

-Chemotactic Agents

6

Where do immature T lymphocytes first enter the thymus?

the cortex

7

Where are Hassall's Corpuscles located?

-medulla of the thymus

8

Where do lymphatics enter the lymph node?

on outer convex surface into subcapsular sinus

9

Where are HEV's located? What are they for?

-cortex of lymph nodes

-entrance point for lymphocytes

10

What is located at the center of a B nodule in a lymph node?

Germinal center

11

What makes up the buffy coat of blood?

-Platelets

-Leukocytes

12

What cells are leukocytes (white blood cells)?

-Neutrophils

-Lymphocytes

-Monocytes

-Eosinophils

-Basophils

13

What leukocytes are granulocytes?

-neutrophils

-Eosinophils

-Basophils

14

What leukocytes are Agranulocytes?

-Lymphocytes

-Monocytes

15

What are the histological markers of neutrophils?

-few granules

-three lobed nucleus

16

What are the functions of eosinophils?

-killer of parasites

-not phagocytic: they release their enzymes via exocytosis

-also modulate allergic inflammation to counteract histamine etc

17

What are the histological markers of lymphocytes?

-Large nucleus, a little bit bigger than RBCs

-Small amount of basophilic cytoplasm

18

What kind of surface marker (CD) is on B lymphocytes?

CD20+

19

What kind of stem cell do eosinophils, basophils, neutrophils, monocytes, erythrocytes, and platelets derive from?

-Myeloid stem cell

20

What kind of stem cell do lymphocytes derive from?

-lymphoid stem cell

21

Which antibodies act as receptors on the surface of B Lymphocytes?

IgM & IgD

22

Humoral Immunity = ?

Antibodies & B Cells

23

Cellular Immunity = ?

T Cells

24

What chemicals stimulate Cytotoxic T Lymphocytes to undergo clonal expansion?

IL-2

gamma-interferon

25

What's the difference between basophils and mast cells?

Basophils are still circulating, mast cells are in tissue

26

What is the complement system?

-20 proteins that work together to destroy invaders

-humans born with defects in complement system don't live long

-Classical pathway depends on antibodies

27

Which protein initiates the "alternative" pathway for complement activation?

C3b

28

How do complement proteins eventually destroy bacteria?

-C3bBb cleaves more C3 as well as C5

-C5b, C6, C7, and C8 form a stalk that anchors the membrane attack complex (MAC) in the bacterial cell wall

-C9 comes along and makes a channel that opens a hole in the surface of the bacterium

29

Which proteins on human cells prevents complement from destroying friendlies?

-MCP (clips C3b)

-DAF (decay accelerating factor) (accelerates degradation of C3bBb)

30

What is a third complement activation pathway aside from the classical (antibody dependent) and alternative (antibody independent) pathways? What initiates this pathway?

-lectin activation pathway

-initiated by mannose-binding lectin (MBL)

31

What does iC3b do?

-inactivated C3b

-cannot form Membrane Attack Complex (MAC)

-opsonizes invaders to facilitate phagocytosis by macrophages

32

How do natural killer cells kill cells?

-induce apoptosis via an injection system

-introduce granzyme B into target cell

-NK cell interacts with Fas on surface of target, inducing apoptosis

33

Where are proteins of the complement system produced?

Liver

**think about cirrhosis

34

What protein does C3bBb cleave?

C3

also C5

35

What does the MASP protein do in the lectin activation pathway?

cleaves C3

36

What do C3a and C5a do?

-act as chemoattractants to attract more macrophages and neutrophils

37

Where does LPS come from? What does it do?

-Gram negative bacteria

-binds to receptors on primed macrophages and makes them angry