The Immune System (Lyons) Flashcards Preview

CSF Block 2 > The Immune System (Lyons) > Flashcards

Flashcards in The Immune System (Lyons) Deck (25):
1

what are the formed elements in blood?

RBC, leukocytes, megakaryocyte fragments, platelets

2

what are the organic/inorganic substances in blood

plasma proteins (albumin, fibrinogen, globulins)

AA, vitamins, hormones, nutrients, wastes, etc.

3

structure of RBC

no nucleus
biconcave disk
8 micrometers in diameter

4

what are platelets?

fragments of megakayocyte cells in bone marrow

5

whats the function of platelets?

hemostasis. doesn't leave the blood

6

what are the granulocytes

neutrophils aka polymorphonuclear cell
eosinophils
basophils
monocytes
NK cells
lymphocytes

7

Neutrophils: size, morphology, function

9-12 micrometers

segmented nucleus, 3-5 lobes

chemotactically attracted to inflammation sites; phagocytosis of bacteria

8

Eosinophils: size, morphology, function

10-12 micrometers

bilobed nucleus, large cytoplasm, eosinophilic lysosomes

chemotactically attracted to inflammation sites by eosinophil chemotactic factor released by mast cells or parasites; neutralize histamine; inhibit mast cells; phagocytose Ag-Ab complex in allergic response

9

Basophils: size, morphology, function

9-12 micrometers

lobed nucleus, masked by large basophilic granules in cytoplasm

similiar to mast cells (secrete same substances, same primary/secondary IgE response)

10

Monocytes

12-30 micrometers

large, eccentric, horseshoe shaped nucleus

differentiate into macrophages in CT, dendritic cells, osteoclasts/blasts of bone/cartilage

11

Natural Killer cell function

innate immune system lymphocytes that are cytolytic

12

Lymphocytes: size, morphology, function

small (6-9 micrometers), medium (10-12 micrometers), large (12-18 micrometers)

round, dense heterochromatic nucleus; larger the cell, larger the nucleus and more cytoplasm

cell surface receptors facilitate cell migration, response to foreign and self Ag

13

innate vs. adaptive immunity

innate - neutrophils/macrophages phagocytose Ag

adaptive - lymphocytes neutralize and destory Ag

14

cell mediated immunity vs. antibody mediated immunity

CMI - t cells directly attack intracellular Ag

AMI - extracellular Ag destroyed by Ab secreted by B cell that helps destroy/neutralize Ab

15

what are the primary lymphoid organs and where do B cells and T cells mature?

Thymus (T cells)
Bone marrow (B cells)

16

what are the secondary lymphoid organs?

lymph nodes, spleen, diffuse lymphatic tissue

17

how does the thymus development in comparison to the rest of the body?

greatest size during fetal stage, then grows more slowly. regresses and thymic tissue replaced by adipocytes

18

what are the two lobules of the thymus and their morphology

cortex - dark staining, isolated compartment supported by reticular epithelia
medulla - light staining, continuous

19

what surrounds the thymus?

loose CT that blends w/ surrounding CT

20

what are trabeculae

connective tissue that is continuous with the capsule

separates lobules

21

how are the 6 types of reticular epithelial cells distributed?

three in cortex
three in medulla

22

what are the two main functions of reticular epithelia cells?

barrier - keeps Ag out while T cells mature

T cell maturation - releases hormones and expresses MHC molecules for selection

23

what are hassall's corpuscles, what substances do they release?

densely packed whorls of reticular epithelial cells

release IL-4, IL-7, cytokine thymic stromal lymphopoietin (TSLP)

24

what does thymic stromal lymphopoietin (TSLP) do?

increases dendritic cell ability to convert naive thymocytes to regulatory T cell lineage

25

what types of cells are in the thymus

macrophages
CT cells
small, medium, large T lymphocytes