Anatomy and Physiology II Practice Test

Aplastic anemia is characterized by the failure of the bone marrow to produce an adequate number of blood cells. This condition arises from the destruction of blood-forming cells in the bone marrow, leading to a deficiency in red blood cells, white blood cells, and platelets. The bone marrow essentially becomes aplastic, meaning it doesn’t produce enough healthy blood cells.

This can stem from various factors, including autoimmune diseases, exposure to toxic substances, certain medications, and viral infections, which damage the stem cells responsible for blood production. As a result, individuals may experience symptoms associated with low levels of all types of blood cells, such as fatigue, increased susceptibility to infections, and excessive bleeding or bruising.

In contrast, other forms of anemia mentioned are related to different underlying causes. Hemorrhagic anemia involves blood loss leading to a reduction in red blood cells, pernicious anemia is primarily due to a deficiency of vitamin B12 affecting red blood cell production, and sickle cell anemia results from a genetic mutation that affects the shape of red blood cells. Thus, it is the specific destruction of the bone marrow’s blood-forming capacity that defines aplastic anemia.