Understanding the Role of the Spleen as a Blood Reservoir

Why do biologists refer to the spleen as a blood reservoir?

A. To store extra blood
B. To generate new blood cells
C. To regulate immune functions
D. To produce antibodies

Answer:

A. To store extra blood

Biologists refer to the spleen as a blood reservoir because it has the ability to store extra blood. The spleen contains two types of tissue: red pulp and white pulp. The red pulp consists of cavities that store blood, where damaged red blood cells are removed and new ones are generated.

The white pulp is packed with lymphocytes that play a role in immune functions, such as removing antigen-coated bacteria from the blood. The spleen, by holding a reserve of blood, plays an essential part in the circulatory system and in instances where extra blood is needed, the spleen can contract to release this stored blood into circulation.