Fundamentals of Nursing Q 273
The primary purpose of a platelet count is to evaluate the:
A. Potential for clot formation
B. Potential for bleeding
C. Presence of an antigen-antibody response
D. Presence of cardiac enzymes
Correct Answer: A. Potential for clot formation
Platelets are disk-shaped cells that are essential for blood coagulation. A platelet count determines the number of thrombocytes in blood available for promoting hemostasis and assisting with blood coagulation after injury. Platelets, also called thrombocytes, are tiny fragments of cells that are essential for normal blood clotting. They are formed from very large cells called megakaryocytes in the bone marrow and are released into the blood to circulate. The platelet count is a test that determines the number of platelets in your sample of blood.
Option B: It also is used to evaluate the patient’s potential for bleeding; however, this is not its primary purpose. The normal count ranges from 150,000 to 350,000/mm3. A count of 100,000/mm3 or less indicates a potential for bleeding; count of less than 20,000/mm3 is associated with spontaneous bleeding.
Option C: Platelets, the smallest of our blood cells, can only be seen under a microscope. They’re literally shaped like small plates in their inactive form. A blood vessel will send out a signal when it becomes damaged. When platelets receive that signal, they’ll respond by traveling to the area and transforming into their “active” formation. To make contact with the broken blood vessel, platelets grow long tentacles and then resemble a spider or an octopus.
Option D: If you have too many platelets, it can increase your risk for clotting. But often your cardiovascular risk has more to do with platelet function than platelet number. For example, you could have a healthy number of platelets, but if they’re sticking together too much it can increase your chance of having a heart attack or stroke.