Spleen

The image depicts a simplified diagram of the spleen anatomy. The spleen is an organ located in the upper left part of the abdomen, playing a vital role in the body’s immune response and the destruction and recycling of old red blood cells.

The outermost layer of the spleen is known as the capsule, a thin, fibrous layer that encases the organ, providing protection and structural integrity. Branching from the capsule inward are trabeculae, which are fibrous bands that extend into the body of the spleen, providing an internal support framework.

Within the spleen, there are two distinct types of tissue marked as white pulp and red pulp. The white pulp appears as small, roundish areas and is associated with the immune function of the spleen. It contains lymphocytes and macrophages which are key in fighting infection. The red pulp surrounds the white pulp and is involved in filtering and breaking down old red blood cells. It’s marked by a network-like structure that reflects its role in filtering the blood.

The vasculature of the spleen is highlighted, showing an artery entering the organ, branching out, and then smaller vessels dispersing throughout the red pulp. These vessels are termed vascular sinuses or sinusoids, which are enlarged spaces or channels where blood is exposed to the macrophages of the red pulp for monitoring and phagocytosis of old and defective blood cells.

Finally, the term ‘vien’ appears to be a misspelling of ‘vein’, indicating the vessel through which purified blood exits the spleen to rejoin the systemic circulation. The spleen’s function in the circulatory system is crucial, as it serves as a site for hematopoiesis, immune surveillance, and response, as well as the removal and recycling of aged erythrocytes.

TermDefinition
CapsuleThe outermost layer of the spleen, providing protection and structural integrity.
TrabeculaeFibrous bands branching from the capsule into the spleen, providing internal support.
White PulpTissue in the spleen associated with immune function, containing lymphocytes and macrophages.
Red PulpTissue involved in filtering and breaking down old red blood cells, surrounding the white pulp.
Vascular SinusesEnlarged spaces or channels in the spleen where blood is exposed to macrophages for phagocytosis.
VeinThe vessel through which purified blood exits the spleen to rejoin the systemic circulation.