Anatomy and Physiology II Practice Test

Leukopenia is defined as a decrease in the number of white blood cells (leukocytes) in the bloodstream. This condition can result from a variety of factors, including certain infections, autoimmune diseases, medications, or bone marrow disorders, which hinder the body’s ability to produce sufficient white blood cells needed for immune function.

White blood cells are essential for the immune system as they help the body fight off infections and other diseases. When their levels are low, it can lead to increased susceptibility to infections, since the body’s defenses are compromised. Understanding this condition is crucial for diagnosing and managing various health issues that may lead to weakened immune responses.

The other answer choices describe different conditions: an increase in red blood cells refers to polycythemia, an increase in white blood cells is known as leukocytosis, and a decrease in platelets is termed thrombocytopenia. Each of these conditions affects different components of the blood and indicates distinct pathological processes.