The Spleen

Question 1

Where is the spleen?

Answer 1

The spleen is an organ located on the left side of the abdominal cavity under the diaphragm

Question 2

The spleen is the largest ________ organ in the body, is the size of a _______, and weighs ________.

Answer 2

Lymphatic
Fist
160g

Question 3

Unlike lymph node, the spleen does not have any _____ lymphatic vessels.

Answer 3

afferent (sensory)

Question 4

What is the splenic capsule made from?

Answer 4

Fibrous CT
Elastic fiber
Smooth muscle

Question 5

What extends from the splenic capsule into the organ?

Answer 5

Trabeculae

Question 6

What is the indention of the spleen called?

Answer 6

Hilus

Question 7

What is in the hilus?

Answer 7

Where the splenic vessels enter and exit

Question 8

Is the spleen a vital organ for adults?

Answer 8

No. But it helps other organs

Question 9

What are three functions of the spleen?

Answer 9

Destroys worn-out RBCs- Red pulp
Monitors blood for foreign antibodies- White pulp
Acts as a blood reservoir

Question 10

What does the spleen do for the fetus?

Answer 10

Is an important site for RBC production (and very anemic adults)

Question 11

What forms the spaces where splenic pulp is found?

Answer 11

Trabeculae

Question 12

What are the two kinds of splenic pulp? In what percentages?

Answer 12

Red- 75%

White- 25%

Question 13

What is red pulp associated with?

Answer 13

Venous return

Question 14

How is red pulp “gorged”?

Answer 14

Consists of RBCs which are packed particularly close together in sinuses

Question 15

What does red pulp do to old RBCs?

Answer 15

Recycle iron and globulins

Turns heme into bilirubin

Question 16

What is white pulp associated with?

Answer 16

Arterial supply

Question 17

What leukocytes are found in white pulp?

How are they arranged?

Answer 17

Consists of lymphocytes and macrophages, aggregated like sleeves along small branches of the splenic artery

Question 18

What does white pulp look like histologically?

Answer 18

In tissue sections, the white pulp appears as an ovoid mass of lymphocytes with an arteriole passing through it in a “sea” of red pulp

Question 19

How and why can the spleen change in size?

Answer 19

The spleen is able to make rapid changes in volume due to elastic fibers and smooth muscle in the capsule. Contraction of the spleen increases the number of RBCs in circulation.
During hard exercise, splenic volume can be reduced 40-50%