Q: Which of the following is the correct formula for calculating the number of RBCs per microliter ($$\mu L) $$using a hemacytometer?

$$\text{Cells}/\mu L = \dfrac{\text{Avg} \times \text{DF}}{A \times D}$$

Question 1

Which of the following best describes the primary function of neutrophils in the human body?

Accepted Answer

They destroy bacteria through phagocytosis and the action of digestive enzymes in their granules.

Question 2

A patient presents with an increased number of eosinophils in their blood. Which of the following conditions is most likely associated with this finding?

Accepted Answer

Allergic reaction or parasitic infection

Question 3

Which of the following statements about platelets (thrombocytes) is TRUE?

Accepted Answer

Platelets are essential for blood clotting and maintaining vascular integrity.

Question 4

During a manual RBC count using a hemacytometer, a 1:200 dilution is used. If you count a total of 1020 cells on both sides, what is the average number of cells per side?

Accepted Answer

$$510$$

Question 5

Which of the following best explains why ammonium oxalate is used as a diluting fluid for WBC and platelet counts in a hemacytometer?

Accepted Answer

It lyses RBCs, allowing for easier identification and counting of WBCs and platelets.

Question 6

A laboratory technician is counting WBCs using a hemacytometer. Which cells should be counted according to the standard boundary rule?

Accepted Answer

Cells within the square and those touching the left or top boundaries

Question 7

Which of the following is the correct formula for calculating the number of RBCs per microliter ($$\mu L) $$using a hemacytometer?

Accepted Answer

$$	ext{Cells}/\mu L = \dfrac{	ext{Avg} 	imes 	ext{DF}}{A 	imes D}$$

Question 8

A blood smear shows an increased number of band neutrophils. What does this most likely indicate?

Accepted Answer

An acute bacterial infection causing a left shift in neutrophil maturation

Question 9

Which of the following best distinguishes monocytes from other leukocytes in a peripheral blood smear?

Accepted Answer

They are the largest leukocytes, with abundant blue-gray cytoplasm and a horseshoe-shaped or folded nucleus.

Question 10

A patient’s WBC count is performed using a hemacytometer. The average number of cells counted is 58. Using the formula $$	ext{WBC} = [	ext{avg} + (0.1 	imes 	ext{avg})] 	imes 100$$, what is the calculated WBC count?

Accepted Answer

$$6380$$

Question 11

Which of the following is a qualitative evaluation in hematology?

Accepted Answer

Examining the shape and appearance of blood cells under a microscope

Question 12

Which of the following best describes the function of basophils?

Accepted Answer

They release histamine and heparin during immediate hypersensitivity reactions.

Question 13

Which of the following is a correct statement about lymphocytes?

Accepted Answer

They are associated with viral infections and comprise about 34% of leukocytes in adults.

Question 14

A laboratory is using a hemacytometer with a depth of $$0.1\ 	ext{mm}$$ and an area counted of $$0.2\ 	ext{mm}^2. If $$the average number of RBCs counted is $$510$$ and the dilution factor is $$200$$, what is the calculated RBC count per microliter ($$\mu L$$)? Use the formula $$	ext{Cells}/\mu L = \dfrac{	ext{Avg} 	imes 	ext{DF}}{A 	imes D}.$$

Accepted Answer

$$5,100,000 ($$calculation: $$\dfrac{510 	imes 200}{0.2 	imes 0.1} = 510 	imes 200 / 0.02 = 102,000 / 0.02 = 5,100,000)$$

Question 15

Which of the following best describes the difference between granulocytes and agranulocytes?

Accepted Answer

Granulocytes contain visible cytoplasmic granules, while agranulocytes do not.

Question 16

Which of the following is the correct sequence of maturation for neutrophils in the bone marrow?

Accepted Answer

Myeloblast → Progranulocyte → Myelocyte → Metamyelocyte → Band → Segmented neutrophil

Question 17

A patient with a parasitic tissue infection is likely to show an increase in which type of leukocyte, and what is the typical appearance of this cell?

Accepted Answer

Eosinophil; red-orange granules in a colorless cytoplasm

Question 18

Which of the following best describes the role of platelets in the vascular system?

Accepted Answer

They maintain the structure and integrity of the endothelium by plugging gaps and participating in clot formation.

Principles and Practice of Clinical Hematology: Blood Cells and Their Evaluation

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