Final answer:
HCT category refers to hematocrit, which measures the volume percentage of erythrocytes in blood. A hematocrit level of 42 percent means that 42 percent of the blood volume is red blood cells. The formed elements include erythrocytes, leukocytes, and thrombocytes, and not all are complete cells, hence why they are not all referred to as cells.
Step-by-step explanation:
The term HCT category refers to the hematocrit level, which is the volume percentage of erythrocytes (red blood cells) in a sample of centrifuged blood. Hematocrit is an important parameter in blood tests because it helps to assess the proportion of red blood cells in the blood, which is essential for delivering oxygen throughout the body. For example, a patient's hematocrit of 42 percent indicates that 42 percent of their blood volume is composed of red blood cells, and the remaining 58 percent is primarily plasma, the liquid component of blood.
Regarding the formed elements of blood, it would be incorrect to refer to them as cells because some of the formed elements, like platelets, are actually fragments of cells rather than complete cells. The formed elements include erythrocytes, leukocytes (white blood cells), and thrombocytes (platelets), which all play different roles in the circulatory system and immune response.