Spleen Flashcards
Which surface does the spleen have impressions on?
Medial surface
What are the impressions on the medial surface of the spleen?
Gastric impression
Renal impression
Colic impression
Where does the spleen lie in relation to the stomach?
Lies behind the stomach
Where does the spleen lie in relation to the kidneys and colon?
Lies above the kidneys and colon
What is the blood supply of the spleen?
Aorta
coeliac trunk branches off aorta
splenic artery branches off coeliac trunk
What is the blood drainage of the spleen?
Splenic vein
exits spleen
feeds into hepatic portal vein
Where do blood vessels enter and leave the spleen?
Hilum located on medial surface
What is the spleen made up of?
Red pulp
White pulp
What is red pulp made up of?
Sinuses - large capillaries, gaps in their endothelium
endothelium is lined by macrophages
and cords of connective tissue
What is white pulp made up of?
Similar structure to lymphoid follicles
so germinal centre, B cells etc.
Which parts of the spleen do the different blood components pass through?
Red cells preferentially pass through red pulp
White cells and plasma preferentially pass through white pulp
What are the four main functions of the spleen?
Macrophages remove old, damaged, abnormal red blood cells from blood
destroy them by phagocytosis
Pooling of blood
Extramedullary haemopoiesis
Immunological function
What is the use of pooling of blood in the spleen?
Platelets and red cells can be rapidly mobilised during bleeding
When does extramedullary haemopoiesis occur?
Bone marrow fails
Cells are dying quickly
How does the spleen have an immunological function?
Contains significant amount of body’s T cells and B cells
What is splenomegaly?
Enlarged spleen
How do you examine for splenomegaly?
Palpate at right iliac fossa
move hand diagonally upwards, palpate at regular intervals
What are the results of an examination if there actually is splenomegaly?
Can palpate spleen below the costal margin
which is always abnormal