The spleen is a saclike mass of lymphatic tissue located in the left upper quadrant of the abdomen. Its function is to filter microoganisms and other foreign material from the blood, as well as, to form lymphocytes and monocytes which are part of the immune function. In addition, the spleen destroys worn-out red blood cells liberating the hemoglobin; this final function is termed a/an _ activity.
The correct answer and explanation is:
The correct answer is phagocytic activity.
Explanation:
The spleen is a vital organ involved in both the immune system and the circulatory system. One of its key roles is the removal of aged or damaged red blood cells (RBCs) from the bloodstream. This process is achieved through phagocytosis, a cellular activity where specialized cells engulf and digest cellular debris, pathogens, and worn-out cells.
In the spleen, macrophages—large phagocytic cells—line the sinusoids of the red pulp, the area responsible for filtering blood. These macrophages recognize aged or defective RBCs and engulf them through phagocytosis. Once inside the macrophages, the RBCs are broken down, and their components are recycled. Hemoglobin, the oxygen-carrying molecule inside RBCs, is broken down into heme and globin. The heme is further degraded to release iron and biliverdin (which is converted to bilirubin), while the globin is broken down into amino acids. The iron is reused in the body for the production of new RBCs in the bone marrow.
This phagocytic activity of the spleen serves multiple purposes:
- Blood Filtration: It removes old and damaged RBCs, preventing them from causing blockages or impairing oxygen delivery.
- Recycling Resources: The spleen recycles valuable materials like iron, which is essential for new RBC synthesis.
- Immune Defense: The phagocytic cells in the spleen also engulf microorganisms and foreign particles, contributing to immune surveillance.
In summary, the spleen’s destruction of worn-out red blood cells by engulfing and breaking them down is a phagocytic activity. This process not only maintains healthy blood but also supports the immune system by clearing harmful agents from circulation.