NBCE Exam 2026 – 400 Free Practice Questions to Pass the National Board of Chiropractic Examiners

The primary function of the spleen in the immune system is to filter blood. The spleen plays a crucial role in the body's immune response by monitoring the blood for pathogens, such as bacteria and viruses. It contains immune cells that can identify and respond to these foreign invaders. The organ acts as a blood reservoir and filters out old or damaged red blood cells, as well as debris and pathogens. This filtering process helps maintain the health of the blood and supports the immune system's ability to fight infections effectively.

In this context, while insulin production relates to the pancreas, hormone production may occur in different glands throughout the body, and calcium storage is primarily a function of the bones, these options do not accurately reflect the spleen's role in immunity and blood management. Thus, filtering blood is a vital and distinct function of the spleen that affirms its importance in the immune system.