Which of the following functions is associated with the spleen?
A Producing coagulation factors
B Destroying dying red blood cells
C Producing leukocytes before birth
D Storing glycogen
The Correct Answer and Explanation is:
The correct answer is B. Destroying dying red blood cells.
The spleen is a vital organ in the lymphatic and immune systems with several key functions, particularly related to the blood and immune system. Its role in the destruction of dying red blood cells is one of its most significant functions. Here’s a detailed explanation:
Functions of the Spleen
- Destruction of Dying Red Blood Cells:
The spleen is primarily responsible for the breakdown and removal of old or damaged red blood cells (RBCs) from the bloodstream. This process occurs in the spleen’s red pulp, a specialized tissue within the organ. As red blood cells age, they become less flexible and more prone to rupture. The spleen’s macrophages, a type of white blood cell, engulf and digest these aged RBCs, breaking them down into their component parts. Hemoglobin, a key component of RBCs, is broken down into heme and globin. The iron from heme is recycled and transported back to the bone marrow for the production of new RBCs, while the heme is converted to bilirubin and eventually excreted through bile. - Production of Leukocytes Before Birth:
During fetal development, the spleen is one of the organs involved in the production of white blood cells (leukocytes). This function is crucial as the fetal bone marrow and liver initially handle hematopoiesis (the formation of blood cells), but the spleen also contributes to this process before birth. After birth, the bone marrow becomes the primary site for leukocyte production. - Storing Blood and Immune Responses:
The spleen has the capacity to store blood and release it into circulation when needed, such as in cases of hemorrhage. Additionally, it plays a role in immune responses by filtering pathogens and presenting them to lymphocytes, which helps in the production of antibodies and the activation of immune responses. - Coagulation Factors and Glycogen Storage:
The spleen does not produce coagulation factors; this is the role of the liver. Similarly, glycogen storage is primarily managed by the liver and muscles, not the spleen.
In summary, the spleen’s most critical and unique function among the provided options is the destruction of dying red blood cells. This process helps maintain a healthy balance of blood cells and contributes to the recycling of essential components, such as iron, for ongoing blood production.