Cells of the immune system Flashcards Preview

HD exam one > Cells of the immune system > Flashcards

Flashcards in Cells of the immune system Deck (44):
1

Hematopoietic cells

Progenitor cells from which all differentiated blood cell types arise during the process of hematopoiesis

2

Where do HSCs sit in the bone marrow?

In a niche of osteoblasts or in sinusoidal endothelial cells

3

What is the purpose of the HSCs being in a niche?

The niche has all the growth factors and other renewal factors that are needed

4

Can HSCs be in the plasma?

Yes, but growth factors in the bone marrow encourage them to "home" back to the niches

5

HSC maintenance is also affected by what type of cell?

Stromal cells

6

What else do stromal cells do?

They push the HSCs toward differentiation to a certain type of progenitor cell

7

What two types of cells can a HSC become?

Lymphoid or myeloid progenitor

8

Common myeloid progenitors can become what types of cells?

Thrombocytes, red blood cells, granuloctes (e.g., mast cells), basophils, neutrophils, monocytes, or eosinophils

9

What can monocytes become?

Dendritic cells or tissue macrophages

10

Common lymphoid progenitors become what types of cells?

B cells, T cells, or NK cells

11

Principal cytokines for myeloid progenitors

IL-3 and GM-CSF

12

Principal cytokines for lymphoid progenitors

IL-7

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Principal cytokines for basophils

IL-4

14

Principal cytokines for neutrophils

G-CSF

15

Principal cytokines for eosinophils

IL-5

16

Principal cytokines for monocytes/macrophages

GM-CSF &/or M-CSF

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Principal cytokines for dendritic cells

Flt3L

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Principal cytokines for B cells

Many, including IL-3 and IL-7

19

Principal cytokines for T cells

IL-2 and IL-7

20

How do activated lymphocytes get from lymph nodes into circulation?

First go through the lymph tissue to the thoracic duct, then dump into somatic circulation

21

What is another name for neutrophils?

Polymorphonuclear neutrophilic lymphocytes (PMNs)

22

What type of cell are neutrophils?

Granulated myeloid cells; not very acidic or basic

23

What is special about neutrophils?

They are the most abundant cell and are the "front line" in the innate immune response

24

What is the lifespan of a neutrophil?

Short; they usually only phagocytose once and then die

25

What is extracellular killing?

The neutrophils, if not large enough to phagocytose the pathogen, can release antimicrobial granules out into the mileau (which will also cause local tissue damage)

26

NETs

Neutrophil extracellular traps - contain the granular enzymes and killing molecules, but also DNA that immobilize pathogens

27

Clinical representation of neutrophil invasion

Pus

28

General information about macrophages

Derived from circulating monocytes
Not very granular
Highly active nucleus for constant transcription
Have a lot of lysosomes for killing

29

Can macrophages be antigen presenting cells?

Yes.

30

Describe the immune response by macrophages over the course of infection.

They are originally not large in number at the infection site, but those that are present will help with recruitment. Once recruitment takes place, the presence of T cells will help with proliferation of macrophages and their response becomes much greater.

31

Macrophages are strong recruiters of what process?

The inflammatory response

32

Primary focus of dendritic cells

Antigen presentation

33

Methods environmental sampling by dendritic cells

Phagocystosis or macropinocytosis

34

Why are dendritic cells so important?

They are the link between innate response and adaptive response; without them, there would be a very weak T cell response to any foreign invader

35

General features of eosinophis

Bilobed; absorb the eosin stains really well and turn bright pink. Neutralize and destroy parasitic invaders.

36

What is contained within eosinophils, and what does that mean for the body?

They have a lot of enzymes and molecules that cause tissue destruction, vasodilation, and inflammatory response; must be very tightly regulated by the immune system

37

Where are eosinophils usually found?

They are scarce, but usually reside in subepithelial connective tissue

38

In what are eosinophils important clinically?

The allergic response

39

General information about mast cells

Large, mononuclear cells that are filled with dark, basophilic granules mainly containing histamine.

40

What is the main job of mast cells?

To "open vascular doors;" they degranulate vasoactive substances during an infection and cause vasodilation, increased permeability

41

Basophils

Accomplice to mast cells and eosinophils; 2-3 lobes

42

Natural killer cells - appearance

Large, mononuclear cells that are distinctively granular.

43

Against what are NK cells aimed?

Viruses and tumor cells

44

Why are NK cells so important?

They are very much like lymphocytes, but they are innate so they act quickly at killing a pathogen while the adaptive immune response is "gearing up"