Emergency Medical Technician (EMT) Intermediate Practice Exam

Which cells are responsible for the destruction of nonfunctional erythrocytes in the spleen?

1. Neutrophils

2. Macrophages

3. Lymphocytes

4. Basophils

The correct answer is: Macrophages

The correct answer is macrophages, which play a key role in the immune system's ability to clear out nonfunctional or old erythrocytes (red blood cells). Located in the spleen, macrophages are specialized cells that can engulf and digest cellular debris and pathogens through a process known as phagocytosis. When red blood cells become damaged or age, they lose their flexibility and ability to effectively transport oxygen. The spleen acts as a blood filter, and macrophages identify these nonfunctional erythrocytes. Once identified, the macrophages engulf the cells, breaking them down and recycling essential components like iron and globin, which can then be repurposed for the production of new blood cells. Other cell types mentioned do not specialize in the destruction of erythrocytes. Neutrophils are primarily responsible for fighting infections, particularly bacterial and fungal infections. Lymphocytes are central to the adaptive immune response, involved in targeting specific pathogens. Basophils play a role in inflammatory responses and allergic reactions, but they are not involved in the process of eliminating erythrocytes in the spleen. Thus, macrophages are the key players in this specific function of blood cell maintenance.