The Spleen Flashcards
Where is the spleen?
The spleen is an organ located on the left side of the abdominal cavity under the diaphragm
The spleen is the largest ________ organ in the body, is the size of a _______, and weighs ________.
Lymphatic
Fist
160g
Unlike lymph node, the spleen does not have any _____ lymphatic vessels.
afferent (sensory)
What is the splenic capsule made from?
Fibrous CT
Elastic fiber
Smooth muscle
What extends from the splenic capsule into the organ?
Trabeculae
What is the indention of the spleen called?
Hilus
What is in the hilus?
Where the splenic vessels enter and exit
Is the spleen a vital organ for adults?
No. But it helps other organs
What are three functions of the spleen?
Destroys worn-out RBCs- Red pulp
Monitors blood for foreign antibodies- White pulp
Acts as a blood reservoir
What does the spleen do for the fetus?
Is an important site for RBC production (and very anemic adults)
What forms the spaces where splenic pulp is found?
Trabeculae
What are the two kinds of splenic pulp? In what percentages?
Red- 75%
White- 25%
What is red pulp associated with?
Venous return
How is red pulp “gorged”?
Consists of RBCs which are packed particularly close together in sinuses
What does red pulp do to old RBCs?
Recycle iron and globulins
Turns heme into bilirubin
What is white pulp associated with?
Arterial supply
What leukocytes are found in white pulp?
How are they arranged?
Consists of lymphocytes and macrophages, aggregated like sleeves along small branches of the splenic artery
What does white pulp look like histologically?
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
How and why can the spleen change in size?
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%
