Emergency Medical Technician (EMT) Intermediate Practice Exam

What condition is characterized by reduced oxygen-carrying capacity due to abnormally shaped red blood cells?

1. Hemophilia

2. Thalassemia

3. Sickle cell disease

4. Iron deficiency anemia

The correct answer is: Sickle cell disease

Sickle cell disease is characterized by the presence of abnormally shaped red blood cells, which take on a crescent or "sickle" shape. This deformation of the cells arises from a genetic mutation that affects hemoglobin, the protein in red blood cells that carries oxygen. The sickle-shaped cells are not only less efficient at transporting oxygen due to their abnormal shape but also have a tendency to clump together, which can lead to blockages in blood vessels and reduced blood flow. This condition can cause episodes of pain, known as sickle cell crises, as well as various complications, including increased risk of infections and organ damage. Other conditions listed do not primarily involve the shape of red blood cells. Hemophilia is a disorder affecting blood clotting due to deficiencies in clotting factors, while thalassemia is a genetic blood disorder that leads to a reduced production of hemoglobin but does not cause the sickle shape in red blood cells. Iron deficiency anemia is related to a lack of iron, leading to reduced hemoglobin production; however, it does not result in abnormally shaped cells. Thus, the unique feature of sickle-shaped red blood cells in sickle cell disease directly ties to the condition's reduced oxygen-carrying capacity