Question 4 - Reading Comprehension Practice Test for the HESI Exam

A complete blood count (CBC) is one of the most useful and requested types of analysis in medical practice. A CBC searches for all the cells that exist in the blood, which are divided into three basic types: white blood cells (leukocytes), platelets, and red blood cells (erythrocytes). All of these blood cells are produced in the bone marrow and correspond to a specific exam, integrated in the CBC: erythrogram, leukogram, and thrombogram.

The erythrogram studies red blood cells. Among other tests, it includes a red blood cell count, a hematocrit, and hemoglobin. When these levels are low, the patient may be suffering from anemia, which can be caused by anything from heavy menstrual bleeding to Addison’s disease. A diagnosis of polycythemia may be made if the number of red blood cells is increased.

The leukogram is the test that evaluates the number of white cells present in the blood, which should vary between 4,000 and 10,000 cells per cubic millimeter in most adults. High values of white blood cells are seen with infection or severe emotional/physical stress, while AIDS and chemotherapy are two causes for low values.

The thrombogram is the analysis of platelets, the cells responsible for coagulation. The main function of platelets is to help stop bleeding by helping form a clot. They do this by secreting proteins from their surface that allow them to stick to vessels and each other. Low values of platelets are seen with pregnancy or an enlarged spleen, whereas high values are seen with cancers or iron deficiency.