Lymphoid System #2

Question 1

Who is the largest lymph organ of all?

Answer 1

Spleen

Question 2

What does a spleen do anyway?

Answer 2

Filters the blood

Question 3

What kinds of splenic pulp are there?

Answer 3

White and Red

Question 4

Where is white pulp?

Answer 4

Surrounding arteries thickening into splenic nodules.

Question 5

Where is the red pulp?

Answer 5

It occurs in irregular masses (splenic cord)

Question 6

The spleen capsule is made of….

Answer 6

connective tissue

Question 7

Where is the tissue capsule the heaviest?

Answer 7

The hilum.

Question 8

Name the structures that come from the capsule branch and anastamose

Answer 8

Trabeculae

Question 9

What supports splenic pulp?

Answer 9

Reticular Fibers

Question 10

As blood vessels leave trabeculae, they are ensheathed in ____. What cells are dense here?

Answer 10

PALS. T cells.

Question 11

Where are splenic nodules found?

Answer 11

Around the central artery.

Question 12

White pulp transitions to red pulp at the ________, which contains the ________.

Answer 12

Marginal Zone. Marginal Sinuses

Question 13

What infiltrated the red pulp

Answer 13

All elements of circulating blood

Question 14

What structures support the red pulp?

Answer 14

reticular fibers and cells

Question 15

Spleens are really good at producing a certain kind of cell. NAME IT

Answer 15

Macrophages

Question 16

Spleen is known for removal of…

Answer 16

senescent RBCs

Question 17

What happens when antigens enter the spleen via the blood?

Answer 17

Detected by antigen presenting cells in splenic nodules

Question 18

What structures support the arteries and veins of the spleen?

Answer 18

Trabeculae

Question 19

When an artery leaves the trabeculae, it becomes known as ________. It will soon be surrounded by ______.

Answer 19

a central artery. Splenic nodules.

Question 20

Central artery –>

Answer 20

Follicular radial arteries –> marginal sinuses –> Pencillar arterioles –> Terminal capillary

Question 21

Describe the cells surrounding the nd part of pencilar arteries

Answer 21

Macrophages, reticular cells and fibers

Question 22

What do terminal capillaries do?

Answer 22

They empty into sinuses (closed circulation) or empty into red pulp (open circulation)

Question 23

The red pulp contains…

Answer 23

venous/splenic sinuses, and splenic cords (cords of Billroth)

Question 24

What divides the thymus into lobules?

Answer 24

Trabeculae

Question 25

What are the two parts of each lobule?

Answer 25

Cortex and medulla

Question 26

The ________ is continuous from lobule to lobule.

Answer 26

Medulla

Question 27

The cortex is mostly made of what two cell types?

Answer 27

T cells and Epithelial Reticular Cells

Question 28

The function of cortical epithelial reticular cells?

Answer 28

T cell selection and Blood-Thymus Barrier

Question 29

The function of medullary epithelial reticular cells?

Answer 29

Governing the differentiation of CD4 and CD8 T cells

Question 30

What cells separate the thymus cortex from its capsule and surround blood vessels?

Answer 30

Cortical ERCs

Question 31

What cell type presents MHC I and II to developing T cells?

Answer 31

Cortical ERCs

Question 32

Describe positive and negative selection of T cells.

Answer 32

``` + = Kill the ones that can't recognize MHC - = Kill the ones that recognize self antigen ```

Question 33

Who gets rid of cells that don't make it through selection?

Answer 33

Macrophages and Dendritic cells in the corticomedullary junction

Question 34

Medullary ERCs produce....

Answer 34

thymic hormones (thymosin, thymopoietin)

Question 35

Blood thymus barrier is made of...

Answer 35

Nonfenestrated capillaries, a thick basement membrane, and a sheath of ERCs. This forms an immunologically sequestered site.

Question 36

The thymus will ______ over time.

Answer 36

Involute

Question 37

What does the spleen do to misshapen cells. Give two examples.

Answer 37

They get trapped in the splenic sinuses and are destroyed by macrophages. Leads to anemia, hyperbilirubinemia, and splenomegaly. Ex. -- Sickle cell, spherocytosis

Question 38

Causes of splenomegaly?

Answer 38

Lots of blood cell breakdown in the spleen, portal hypertension (sometimes from cirrhosis of the liver)

Question 39

What is DiGeorge syndrome?

Answer 39

Inherited immunodeficiency caused by lack of developed cortical cells. This causes no T cell development to occur.