Spleen and Thymus Flashcards Preview

Histology Test 3 Brendan > Spleen and Thymus > Flashcards

Flashcards in Spleen and Thymus Deck (54):
1

The ____ is the largest of the lymphoid organs and is designed for filtering blood,

Spleen

2

The spleen is surrounded by a ____, with _____ passing from it to the interior

capsule
trabeculae

3

There are 2 types of splenic pulp: ___ and ____

red, white

4

____ pulp surrounds and follows arteries. It thickens to form splenic _____

white
nodules

5

____ pulp occurs in irregular masses and forms splenic _____

red
cords

6

The ____ zone is the area between white and red splenic pulp

marginal

7

The connective tissue capsule of the spleen is surrounded by an outer layer of ____. It is heaviest at the ____ where splenic blood enters ____ coming from the capsule.

mesothelium
hilus
trabeculae

8

blood vessels course through the ____

trabeculae

9

Splenic pulp is supported by a meshwork of ______
_____

reticular fibers

10

The spleen has ____ lymphatic vessels in the capsule and large trabeculae. There are no _____ lymphatics

efferent
afferent

11

As blood vessels leave trabeculae they are embedded in the _____ ____ ____, where T cells are concentrated

peri-arterial lymphatic sheath

12

Splenic nodules form along a ____ ____

central artery

13

At the periphery of the white pulp there is a marginal ____ containing ___ ____ where the white pulp transitions to the red pulp

zone
marginal sinuses

14

Splenic ____ pulp is infiltrated with all elements of circling blood.

red

15

The ____ is the greatest producer of macrophages

spleen

16

_____ occurs in the spleen and is the removal of senscent RBC's

erythrophagia

17

Antigens enter the spleen via blood and are detected by ____ presenting cells in ____ ____

antigen
splenic nodules

18

____ ____ in the spleen=where most of the antigen processing occurs

marginal sinuses

19

When arteries leave trabeculae they acquire a lymphatic ____ that is made of primarily _ cells

sheath
T

20

The central artery branches within the nodules to form the ______ arterioles

follicular (Radial)

21

Follicular arterioles empty into ___ ____

marginal sinuses

22

Marginal sinuses then lead to ____ ____, which branch out in the red pulp.

pencillar arterioles

23

The first segment of hte pencillar arterioles retains thin ____ ____ and is called the ____ arteriole

smooth muscle
pulp

24

The second segment of pencillar arterioles aquires a sheath of macrophages, reticular cells, and fibers and is called the _____ arteriole

sheathed

25

The third segment of pencillar arterioles is a ____ ____ that empties directly into sinuses (______ circulation) or directly into the red pulp (____ circulation)

terminal capillary
closed
open

26

Humans have ____ circulation, so arterioles end directly in the red pulp

open

27

Surrounding the white pulp is the ____ ___ which contains venous or splenic sinuses and splenic cords (called cords of _____)

red pulp
bilroth

28

Splenic sinuses have a _____ endothelium

discontinous

29

Each lobule of the thymus (made by ______) has a ___ and a _____

trabeculae
cortex, medulla

30

The ____ of the thymus is continuous from lobule to lobule via a common axial strand.

medulla

31

The cortex of the thymus consists of primarily ____ cells along with ____ ____ cells that are large and pale. Macrophages and lymphocytes are also present

T
epithelial reticular

32

Cortical epithelial reticular cells are ____, where medullary epithelial reticular cells are _____

ectodermal
endodermal

33

The cortical epithelial reticular cells program which ___ cells will die and which ones will live and progress to the medulla.

T

34

Medullar epithelial cells govern the differentiation into _-____ and ____ ___ cells

T helper
T cytolytic

35

Epithelial reticular cells do/do not make reticular fibers

do not

36

Cortical epithelial reticular cells separate ____ from the ___ and also surround blood vessels in the cortex

cortex, capsule

37

Cortical epithelial reticular cells present ____ and ____ complexes to developing ____ cells

MHC1, MHC2
T

38

T-cells that recognize self-MHC but not self antigen are allowed to further _____. Those that cannot recognize MHC are programmed for ____. This is an example of ____ selection

develop
apoptosis
positive

39

T cells that recognize self MHC and self-antigens are eliminated by ____ selection by _____ and ___ cells in the cortico-medullary junction

negative
macrophages, dendritic

40

Most thymic lymphocytes have a ____ life span and undergo ____ in the thymus

short
degeneration

41

Some thymic lymphocytes leave to join the circulating pool via ____ ____ _____

post capillary venules

42

Epithelial reticular cells in the medulla form a epithelial reticular cell____. The medulla also contains the thymic corpuscles (____)

network
Hassals

43

Arteries enter the ____ core and distribute mainly to the ____

medullary
cortex

44

Thymic capilaries have a _____ endothelium and a thick basement membrane with a sheath of ____ ____ cells. This forms the ____ ___ ____

continuous
epithelial reticular
blood thymus barrier

45

Lymphocytes migrate through ____ ___ ____

post capillary venules

46

____ lymphatics in the interlobular connective tissue drain the thymus, There are no ____ lymphatics, no ____, and no _____ present

efferent
aferrent
sinuses, nodules

47

The thymus begins to _____ at puberty, but still functions

involute

48

The hall mark of the thymus medulla is _____ ____

hassal's corpuscle

49

T-cells are derived from ____ ____ ____ _____ ____ but undego differentiation in the _____

bone marrow lymphoid progenitor cell
thymus

50

Thymic differentiation of T cells is in this order: ___-->___-->____

subcortical
cortical
medullary

51

Medullary thymocytes that enter the circulation may be ___ or ____ cells

T-helper
T-cytolytic

52

____ cells and ____ tend to become trapped in splenic sinuses where they are destroyed by _____. This leads to anemia, hyperbilirubenimia, and splenomalgy due to blockage

sickle, spherocytes
macrophages

53

_____ (enlarged spleen) can be due to portal hypertension is often associated with cirrhosis of the liver

splenomegaly

54

_____ syndrome is an inherited immunodefeciency where there is a lack of developed cortical epithelial cells and no T-cell development

digeorge