Question 1

If a capillary tube is not plugged, it must be filled with a special clay before centrifugation.

Accepted Answer

The tube must be sealed to prevent blood splatter during centrifuging.

Question 2

An RBC with a normal amount of hemoglobin is said to be hyperchromic.

Accepted Answer

A hyperchromic RBC is one that has an increased concentration of hemoglobin, resulting in a darker color. A RBC with a normal amount of hemoglobin would be considered normochromic.

Question 3

The life span of an erythrocyte is approximately 120 days.

Accepted Answer

Erythrocytes, also known as red blood cells, have a lifespan of approximately 120 days. After this time, they are removed from circulation and broken down by the spleen and liver.

Question 4

Blood is able to form a clot as the result of a coordinated process involving more than 50 blood factors and processes.

Accepted Answer

More than 30 substances in blood have been found to affect clotting; whether blood coagulates depends on the balance between substances that promote coagulation (procoagulants) and those that inhibit it (anticoagulants).

Question 5

The cytoplasm of lymphocytes stains purple.

Accepted Answer

The cytoplasm of lymphocytes typically stains a pale blue or pale pink color, rather than purple. The nucleus of lymphocytes, however, may appear purple due to the presence of DNA.

Question 6

Hemoglobin A_1c determination is more useful than blood glucose measurement in the management of diabetes, because it provides information on the average blood sugar level over a 2- to 3-month period.

Accepted Answer

Hemoglobin A_1c determination, also known as HbA1c, measures the average blood sugar level over a 2- to 3-month period, whereas blood glucose measurement only provides a snapshot of the blood sugar level at the time of measurement. Therefore, HbA1c determination is more useful in assessing diabetes management and long-term glycemic control.

Question 7

Blood type O is considered the "universal donor," because no anti-A or anti-B antibodies are found in the plasma.

Accepted Answer

Blood type O negative is referred to as the universal donor because it has no circulating antibodies to the ABO antigen nor any Rh antigens that might sensitize an Rh-negative recipient.

Question 8

B cells produce specific antibodies against a particular antigen.

Accepted Answer

B cells are a type of white blood cell that produce specific antibodies against a particular antigen. This is how the immune system is able to recognize and fight off specific pathogens, such as viruses or bacteria.

Question 9

Fasting is necessary before cholesterol testing because HDL and LDL cholesterol are greatly affected by food consumption.

Accepted Answer

Although the total cholesterol and HDL cholesterol levels are not significantly affected by food consumption, the office policy should be followed for patient education in preparation for the test. Most physicians prefer that patients fast for 12 hours before cholesterol levels are checked.

Question 10

The most important red cell index for classification of anemias as macrocytic or microcytic is the mean corpuscular volume.

Accepted Answer

The mean corpuscular volume (MCV) measures the average size of red blood cells and is a key index in determining whether anemia is macrocytic or microcytic. Macrocytic anemias have a high MCV, while microcytic anemias have a low MCV.

Question 11

If the Vacutainer is not completely filled with blood, a FALSE (ESR) reading may result.

Accepted Answer

An incomplete fill of a Vacutainer can alter the blood-to-anticoagulant ratio, potentially affecting the accuracy of the ESR (Erythrocyte Sedimentation Rate) test results.

Question 12

Increases in the WBC count that are not related to disease are seen in pregnant women and individuals facing extreme stress.

Accepted Answer

Increases in WBC count can occur in pregnant women due to hormonal changes and in individuals facing extreme stress due to the release of cortisol. These increases are not necessarily indicative of disease.

Question 13

AST and ALT testing is done to monitor potential liver damage in patients receiving statin drugs.

Accepted Answer

AST and ALT testing is commonly used to monitor liver function in patients receiving statin drugs, as these drugs can cause liver damage in rare cases.

Question 14

An HDL cholesterol level over 20 mg/dL indicates a low risk for cardiac disease.

Accepted Answer

A high HDL cholesterol level is associated with a lower risk of developing heart disease, but an HDL level over 20 mg/dL is abnormally low and may actually increase the risk for cardiovascular disease. The optimal HDL level is generally considered to be above 40 mg/dL for men and 50 mg/dL for women.

Question 15

Lavender-topped tubes are used for routine CBC counts.

Accepted Answer

Lavender-topped tubes are also known as K2-EDTA tubes and are commonly used for routine CBC (complete blood count) tests as they contain an anticoagulant, EDTA, which helps maintain the integrity of blood cells.

Question 16

The WBC count is lowest in newborns and highest in adults.

Accepted Answer

The normal WBC count varies with age. It is higher in newborns and declines throughout life.

Question 17

Eosinophils are phagocytic and are closely associated with allergic reactions.

Accepted Answer

Eosinophils are phagocytic cells that play a role in the immune response to parasitic infections and in allergic reactions, often seen in high numbers in individuals with allergies and asthma.

Question 18

If the shape of RBCs shows significant variation from normal, the alteration in shape is called thrombocytopenia.

Accepted Answer

Thrombocytopenia is a condition characterized by a low number of platelets in the blood, not an alteration in the shape of red blood cells (RBCs).

Quiz 47: Assisting in the Analysis of Blood