Immune System - Spleen VM

Question 1

Identify the white pulp

Identify the red pulp

Answer 1

White pulp: areas of densely-packed lymphocytes

Red pulp: blood-filled sinusoids

Question 2

Describe the action of the spleen on RBCs

Answer 2

The RBCs squeeze through small spaces in the red pulp. Older RBCs are more rigid and tend to lyse during this process. Fragments of destroyed RBCs are then phagocytosed by resident macrophages in the spleen.

Question 3

What is the approximate lifespace of RBCs?

Answer 3

120 days

Question 4

Name the particles that might be observed in the RBCs in the setting of asplenia?

Describe where these come from.

Answer 4

Howell Jolly Bodies

basophilic nuclear remnants found in RBCs. Normally these are removed from young RBCs by splenic macrophages. In the setting of asplenia, these are not not removed.

Question 5

Name three solid organs that have a stroma composed of reticular fibers

Answer 5

spleen, LV, liver

Question 6

What is the Periarterial lymphatic sheath (PALS)?

Answer 6

Tissue consisting of accumulations of T-cells that surround the central arterioles in the white pulp.

Question 7

Name some indications for splenectomy (6)

Answer 7

early sickle cell anemia

infectious mononucleosis

AIDS

bacterial endocarditis

bone marrow tumor replacing normal hematopoiesis

hereditary spherocytosis