measures % hemoglobin spin down blood for hematocrit separates different types of leukocytes in a blood sample Oread the patient’s blood type
The correct answer and explanation is:
Based on the options provided, the correct answer directly related to the procedure described by “spin down blood for hematocrit” is:
spin down blood for hematocrit
Explanation:
The phrase “spin down blood for hematocrit” directly describes the laboratory procedure used to determine the hematocrit. Hematocrit is a vital diagnostic measurement that represents the percentage of blood volume occupied by red blood cells (erythrocytes).
The procedure involves placing a blood sample into a tube (often a capillary tube) and then spinning it at high speed in a centrifuge. Centrifugation separates the blood components based on their density. The densest component, the red blood cells, settles at the bottom of the tube. Above the red blood cells is a thin, whitish layer called the “buffy coat,” which contains the white blood cells (leukocytes) and platelets. The uppermost layer is the plasma, the liquid component of blood.
After centrifugation, the height of the red blood cell column is measured and compared to the total height of the blood sample column. The ratio, multiplied by 100, gives the hematocrit as a percentage. For example, if the red blood cell column is 4 cm high and the total blood column is 10 cm high, the hematocrit is (4/10) * 100 = 40%.
This procedure specifically measures the packed red blood cell volume. It does not directly measure the percentage of hemoglobin (which is typically measured using spectrophotometry after lysing red blood cells), separate different types of leukocytes into distinct layers (leukocytes are in the buffy coat but not sorted by type by this method), or determine a patient’s blood type (which requires serological testing involving antibodies).
Therefore, “spin down blood for hematocrit” is the phrase that accurately identifies both the technique used and the parameter measured in this specific laboratory process among the choices given.