Question 1

Refer to the below table of laboratory values when answering the following questions.
$\begin{array}{|l|l|}\hline \text { Bleeding time (tem plate) } & 2-7 \text { minutes } \\\hline \text { Erythrocyte count } & \begin{array}{l}\text { Male: } 4.3-5.9 \mathrm{million} / \mathrm{uL} \\\text { Female: } 3.5-5.5 \mathrm{million} / \mathrm{uL}\end{array} \\\hline \text { Hematocrit } & \text { Male: } 41 \%-53 \% \\\hline & \text { Female: } 36 \%-46 \% \\\hline \text { Hem oglobin, blood } & \text { Male: } 13.5-17.5 \mathrm{~g} / \mathrm{dL} \\\hline \text { Mean corpuscular hemoglobin } & \text { Female: } 12.0-16.0 \mathrm{~g} / \mathrm{dL} \\25.4-34.6 \mathrm{pg} / \mathrm{cell} \\\hline \text { Mean corpuscular hemoglobin concentration } & 31 \%-36 \% \mathrm{Hb} / \mathrm{cell} \\\hline \text { Mean corpuscular volume } & 80-100 \mathrm{fL} \\\hline \text { Reticulocyte count } & 0.5 \%-1.5 \% \text { of red cells } \\\hline & \\\text { Platelet count } & 150,000-400,000 / \mathrm{uL} \\\hline & \\\hline \text { Leukocyte count and differential } & \\\hline \text { Leukocyte count } & 4500-11,000 / \mathrm{uL} \\\hline \text { Neutrophils } & 54 \%-62 \% \\\hline \text { Eosinophils } & 1 \%-3 \% \\\hline \text { Basophils } & 0 \%-0.75 \% \\\hline \text { Lymphocytes } & 25 \%-33 \% \\\hline \text { Monocytes } & 3 \%-7 \% \\\hline\text { Partial thromboplastin time (activated) } & 25-40 \text { seconds } \\\text { Prothrombin time } & 11-15 \text { seconds } \\\hline \text { Bleeding time } & 2-7 \text { minutes }\\\hline\end{array}$

-Following the donation of a unit of blood, how long before hematocrit begins to increase?

A)1 hour
B)2 hours
C)24 hours
D)5 days
E)2 weeks

5 days

Accepted Answer

The patient's findings of low hemoglobin, leukocyte count, reticulocyte count, and especially the very low platelet count suggest a failure of the bone marrow to produce blood cells, which is characteristic of aplastic anemia.

Question 2

A 65-year-old with persistent diarrhea is found to be severely underweight and to have a hematocrit of 26% with mean corpuscular volume of 110 fl. Her peripheral blood smear shows oversized red blood cells with bizarre shapes. What is the most likely cause of her anemia?

A)Iron deficiency due to intestinal blood loss
B)Absence of erythropoietin because of poor nutrition
C)Gastrointestinal cancer
D)Deficiency of folate, and potentially also vitamin B₁₂
E)Aplastic anemia

D

Accepted Answer

The presence of oversized red blood cells with bizarre shapes seen on the peripheral blood smear indicates megaloblastic anemia, which is commonly caused by a deficiency of folate or vitamin B₁₂. The patient's persistent diarrhea could be causing malabsorption of these vitamins, leading to the anemia. Iron deficiency anemia would typically present with microcytic, hypochromic red blood cells, and absence of erythropoietin would cause anemia of chronic disease, which is not consistent with the peripheral blood smear findings. Gastrointestinal cancer and aplastic anemia are possible causes of anemia but do not explain the specific findings on the peripheral blood smear.

Question 3

Refer to the below table of laboratory values when answering the following questions.
$\begin{array}{|l|l|}\hline \text { Bleeding time (tem plate) } & 2-7 \text { minutes } \\\hline \text { Erythrocyte count } & \begin{array}{l}\text { Male: } 4.3-5.9 \mathrm{million} / \mathrm{uL} \\\text { Female: } 3.5-5.5 \mathrm{million} / \mathrm{uL}\end{array} \\\hline \text { Hematocrit } & \text { Male: } 41 \%-53 \% \\\hline & \text { Female: } 36 \%-46 \% \\\hline \text { Hem oglobin, blood } & \text { Male: } 13.5-17.5 \mathrm{~g} / \mathrm{dL} \\\hline \text { Mean corpuscular hemoglobin } & \text { Female: } 12.0-16.0 \mathrm{~g} / \mathrm{dL} \\25.4-34.6 \mathrm{pg} / \mathrm{cell} \\\hline \text { Mean corpuscular hemoglobin concentration } & 31 \%-36 \% \mathrm{Hb} / \mathrm{cell} \\\hline \text { Mean corpuscular volume } & 80-100 \mathrm{fL} \\\hline \text { Reticulocyte count } & 0.5 \%-1.5 \% \text { of red cells } \\\hline & \\\text { Platelet count } & 150,000-400,000 / \mathrm{uL} \\\hline & \\\hline \text { Leukocyte count and differential } & \\\hline \text { Leukocyte count } & 4500-11,000 / \mathrm{uL} \\\hline \text { Neutrophils } & 54 \%-62 \% \\\hline \text { Eosinophils } & 1 \%-3 \% \\\hline \text { Basophils } & 0 \%-0.75 \% \\\hline \text { Lymphocytes } & 25 \%-33 \% \\\hline \text { Monocytes } & 3 \%-7 \% \\\hline\text { Partial thromboplastin time (activated) } & 25-40 \text { seconds } \\\text { Prothrombin time } & 11-15 \text { seconds } \\\hline \text { Bleeding time } & 2-7 \text { minutes }\\\hline\end{array}$

-Following the donation of a unit of blood, how long before hematocrit begins to increase?

A)1 hour
B)2 hours
C)24 hours
D)5 days
E)2 weeks

5 days

Accepted Answer

After donating a unit of blood, the body begins to compensate for the loss of red blood cells. Hematocrit, which measures the proportion of blood volume that is made up of red blood cells, starts to increase as the body produces more red blood cells to replace those lost. This process does not happen immediately; it takes several days for the body to ramp up production of new red blood cells, with a noticeable increase in hematocrit typically beginning around 5 days after donation.

Question 4

An 82-year-old man presents with fatigue and pallor. His hemoglobin is 7.8, hematocrit is 23.1, leukocyte count is 1,750, and platelet count is 68,000. What is the most likely diagnosis?&#10;A)Blood loss anemia&#10;B)Pernicious anemia&#10;C)Aplastic anemia&#10;D)Hemolytic anemia&#10;E)Sickle cell anemia

Accepted Answer

The combination of a low hemoglobin, hematocrit and platelet count with a low leukocyte count suggests aplastic anemia, a condition where the bone marrow fails to produce enough blood cells. Blood loss anemia would not present with such a low platelet count. Pernicious anemia would present with a low hemoglobin and hematocrit but not a low platelet count. Hemolytic anemia and sickle cell anemia would not present with such a low leukocyte count.

Question 5

How would a cell that has a diameter of 9 micrometers and an mean corpuscular volume of 106 be classified?&#10;A)Macrocyte&#10;B)Microcyte&#10;C)Normal&#10;D)Either normal or slightly microcytic

Accepted Answer

A cell with a mean corpuscular volume of 106 is considered macrocytic if it has a diameter greater than 8 micrometers. Therefore, a cell with a diameter of 9 micrometers and a mean corpuscular volume of 106 would be classified as a macrocyte.

Question 6

Which of the following is tru regarding erythropoietin?&#10;A)Erythropoietin is mainly secreted by the liver&#10;B)Injection of erythropoietin leads to a rapid increase in the number of circulating red blood cells within the next 48 hours&#10;C)Excessive exposure to x-rays with destruction of the bone marrow leads to an increased erythropoietin secretion&#10;D)Erythropoietin also acts on the spleen by decreasing red blood cell destruction

Accepted Answer

Erythropoietin secretion increases in response to decreased oxygen delivery to the kidneys, which can occur with conditions like anemia or hypoxia. Destruction of bone marrow, as seen with excessive exposure to x-rays, impairs the production of red blood cells, leading to anemia and subsequently increased erythropoietin secretion to stimulate red blood cell production.

Question 7

Refer to the below table of laboratory values when answering the following questions.
$\begin{array}{|l|l|}\hline \text { Bleeding time (tem plate) } & 2-7 \text { minutes } \\\hline \text { Erythrocyte count } & \begin{array}{l}\text { Male: } 4.3-5.9 \mathrm{million} / \mathrm{uL} \\\text { Female: } 3.5-5.5 \mathrm{million} / \mathrm{uL}\end{array} \\\hline \text { Hematocrit } & \text { Male: } 41 \%-53 \% \\\hline & \text { Female: } 36 \%-46 \% \\\hline \text { Hem oglobin, blood } & \text { Male: } 13.5-17.5 \mathrm{~g} / \mathrm{dL} \\\hline \text { Mean corpuscular hemoglobin } & \text { Female: } 12.0-16.0 \mathrm{~g} / \mathrm{dL} \\25.4-34.6 \mathrm{pg} / \mathrm{cell} \\\hline \text { Mean corpuscular hemoglobin concentration } & 31 \%-36 \% \mathrm{Hb} / \mathrm{cell} \\\hline \text { Mean corpuscular volume } & 80-100 \mathrm{fL} \\\hline \text { Reticulocyte count } & 0.5 \%-1.5 \% \text { of red cells } \\\hline & \\\text { Platelet count } & 150,000-400,000 / \mathrm{uL} \\\hline & \\\hline \text { Leukocyte count and differential } & \\\hline \text { Leukocyte count } & 4500-11,000 / \mathrm{uL} \\\hline \text { Neutrophils } & 54 \%-62 \% \\\hline \text { Eosinophils } & 1 \%-3 \% \\\hline \text { Basophils } & 0 \%-0.75 \% \\\hline \text { Lymphocytes } & 25 \%-33 \% \\\hline \text { Monocytes } & 3 \%-7 \% \\\hline\text { Partial thromboplastin time (activated) } & 25-40 \text { seconds } \\\text { Prothrombin time } & 11-15 \text { seconds } \\\hline \text { Bleeding time } & 2-7 \text { minutes }\\\hline\end{array}$

-Following the donation of a unit of blood, how long before hematocrit begins to increase?

A)1 hour
B)2 hours
C)24 hours
D)5 days
E)2 weeks

5 days

Accepted Answer

In the fifth month of gestation, the liver is the primary site of fetal hematopoiesis.

Deck 33: Red Blood Cells, Anemia, and Polycythemia