What are some functions of the spleen?

The functions of the spleen include the breakdown of hemoglobin and the formation of bile pigments, which is why the selected answer is correct. The spleen plays a crucial role in the body's immune response, filtering blood, and recycling iron from old red blood cells. When red blood cells are broken down in the spleen, hemoglobin is released and subsequently broken down into its components, including bilirubin, which is a key bile pigment. This process is essential for the management of red blood cell turnover and maintaining proper levels of components involved in blood metabolism.

The other choices pertain to functions that are not performed by the spleen. For example, the production of insulin and glucagon is primarily the function of the pancreas, which regulates blood glucose levels. Secretion of digestive enzymes also occurs in the pancreas and the salivary glands, not in the spleen. Regulation of blood pressure is primarily the function of the cardiovascular system, involving the heart and blood vessels. Each of these systems supports various physiological processes, but they do not overlap with the specific functions of the spleen.