Splenic red pulp
Pulpa rubra
Lymphatic & immuneLymphaticsAbdomenLeft side
- What it is
- The bulk of the spleen: a spongy meshwork of blood-filled sinusoids and cords (of Billroth) packed with macrophages, which gives the organ its dark red colour.
- Function
- Removes old, rigid or parasite-laden red cells, recycles their iron, and holds about a third of the body's platelets in reserve.
- Size
- About 75-80 % of the spleen's volume
- Clinical note
- Red cells must squeeze through 1-3 micrometre slits between the sinusoid lining cells; sickle cells and spherocytes cannot, so they are trapped and destroyed, which is why sickle cell disease causes haemolysis and eventually a scarred, non-functioning "autosplenectomised" spleen.