The liver and spleen are the primary organs responsible for recycling blood, specifically the components of old or damaged red blood cells. While the spleen plays a significant role, recent research highlights the liver as the major site for on-demand red blood cell elimination and iron recycling.
The Liver's Role in Blood Recycling
The liver, through its Kupffer cells (a type of macrophage), plays a crucial role in processing and recycling aged red blood cells. Studies, such as the one published in ScienceDaily (https://www.sciencedaily.com/releases/2016/07/160718132646.htm), have shown that the liver is the main location for this "on-demand" process. This means the liver efficiently removes and recycles red blood cells as needed, maintaining a healthy balance of blood components. The liver also reclaims valuable iron from hemoglobin, a key component of red blood cells, for reuse in creating new red blood cells.
The Spleen's Role in Blood Recycling
The spleen, particularly its red pulp macrophages, also contributes significantly to blood recycling. While not the primary site for on-demand elimination like the liver, the spleen filters blood, identifying and removing aged or damaged red blood cells (https://www.nih.gov/news-events/nih-research-matters/how-spleen-keeps-blood-healthy). Approximately 90% of red blood cell recycling occurs in the spleen, liver, and lymph nodes (https://aklectures.com/lecture/cardiovascular-system/recycling-of-red-blood-cells).
Other Contributing Organs
Lymph nodes also participate in the recycling process, though to a lesser extent than the liver and spleen.
Iron Recycling: A Key Aspect
A vital aspect of blood recycling is the recovery and reuse of iron. Iron from hemoglobin is a crucial component for producing new red blood cells. Both the liver and spleen play critical roles in this iron recycling process, ensuring the body conserves this essential element (https://pmc.ncbi.nlm.nih.gov/articles/PMC8469827/).
