Question 1

Which product of macrophages contributes to increased production of granulocytes by the bone marrow?&#10;A)ICAM-1&#10;B)P-selectin&#10;C)Bradykinin&#10;D)GM-CSF

Accepted Answer

GM-CSF (Granulocyte-Macrophage Colony-Stimulating Factor) is a cytokine produced by macrophages that stimulates the bone marrow to produce more granulocytes. ICAM-1 and P-selectin are adhesion molecules, and bradykinin is a vasoactive peptide, but none of these directly contribute to granulocyte production.

Question 2

A 62 year-old man is found on a routine physical examination to have an enlarged spleen. He is mildly anemic and has a white blood cell count of 29,000 cells/mm3. Review of his medical record shows that his white blood cell count 2 years previously at a community hospital had been 25,000 cells/mm3, and that this abnormal finding had not been followed up. A peripheral blood smear shows a large number of fairly mature-appearing cells that are slightly larger than red blood cells and have a single, round nucleus with scant cytoplasm. What is the most likely diagnosis?

A)Acute myelogenous leukemia
B)Chronic myelogenous leukemia
C)Acute lymphocytic leukemia
D)Chronic lymphocytic leukemia
E)Basophilic leukemia

D

Accepted Answer

The patient's presentation of an enlarged spleen, mild anemia, elevated white blood cell count with fairly mature-appearing cells that are slightly larger than red blood cells, and a single, round nucleus with scant cytoplasm is most consistent with Chronic Lymphocytic Leukemia (CLL). CLL typically presents in older adults and is characterized by an accumulation of functionally incompetent lymphocytes.

Question 3

Which phagocytic cell type leaves the bloodstream soon after an inflammatory response is initiated and accumulates in large numbers at sites of infection?&#10;A)B lymphocyte&#10;B)Basophil&#10;C)Neutrophil&#10;D)Eosinophil&#10;E)Macrophage

Accepted Answer

Neutrophils are the first phagocytic cells to leave the bloodstream and migrate to sites of infection after an inflammatory response is initiated. They accumulate in large numbers at the site of infection and release enzymes to kill invading microorganisms.

Question 4

Neutrophils are capable of all of the following except which one?&#10;A)Diapedesis&#10;B)Phagocytosis of whole red blood cells&#10;C)Ameboid motion&#10;D)Production of proteolytic enzymes for digestion of bacteria

Accepted Answer

Neutrophils are not capable of phagocytosing whole red blood cells as they do not have receptors for recognition and binding of erythrocytes.

Question 5

How long do monocytes/macrophages remain in the tissue?&#10;A)Several minutes&#10;B)Several hours&#10;C)Several days&#10;D)Several months to years

Accepted Answer

Monocytes/macrophages can remain in the tissue for several months to years, where they play a crucial role in immune surveillance, tissue repair, and the removal of dead cells and debris.

Question 6

Basophils share functional and morphological characteristics with which one of the following?&#10;A)Monocytes&#10;B)Macrophages&#10;C)Mast cells&#10;D)Myelocytes

Accepted Answer

Basophils share functional and morphological characteristics with mast cells. Both have granules containing histamine and heparin, and both play a role in allergic reactions and immune responses. Monocytes and macrophages are phagocytic cells involved in the immune response, but they do not have the same granules or histamine releasing capability. Myelocytes are immature blood cells that differentiate into various types of white blood cells, including basophils, but they are not a mature cell type with their own unique characteristics.

Question 7

A patient visits his physician for the examination of a sore on his lip. There was no pain or drainage from the sore. The patient was subsequently admitted to the hospital with a fever. His lab values were: hematocrit of 34%, platelet count of 300,000/uL, and white blood cell count of 4200/uL with 68% lymphocytes and 20% neutrophils. What is the diagnosis of this patient?

A)A mild, nontreatable infection
B)Agranulocytosis
C)Aplastic anemia
D)Acute leukemia
E)Hemolytic anemia

Accepted Answer

The patient has a low white blood cell count with a high percentage of lymphocytes and a low percentage of neutrophils, indicating agranulocytosis, which is a severe reduction in neutrophils.

Question 8

What occurs after activation of basophils?&#10;A)Decreased diapedesis of neutrophils&#10;B)Decreased ameboid motion&#10;C)Contraction of blood vessels&#10;D)Increased capillary permeability

Accepted Answer

Basophils release histamine, which increases the permeability of capillaries, allowing for an immune response to occur.

Question 9

Adhesion of white blood cells to the endothelium is:&#10;A)Due to a decrease in selectins&#10;B)Dependent on activation of integrins&#10;C)Due to the inhibition of histamine release&#10;D)Greater on the arterial than venous side of the circulation

Accepted Answer

Adhesion of white blood cells to the endothelium is dependent on activation of integrins, which allows them to bind to molecules on the surface of the endothelial cells. Selectins actually help facilitate this adhesion process by slowing down the white blood cells and bringing them in closer contact with the endothelium. Histamine release may increase adhesion by inducing the expression of adhesion molecules, but inhibiting histamine release would not decrease adhesion. The adhesion of white blood cells is actually greater on the venous side of the circulation due to lower blood flow and shear stress.

Question 10

A 20-year-old man presents to the emergency department with a 2-week history of diarrhea after a trip out of the country. He is admitted to the hospital for dehydration. His stool specimen is positive for parasitic eggs. Which type of white blood cells would be elevated?

A)Eosinophils
B)Neutrophils
C)T lymphocytes
D)B lymphocytes
E)Monocytes

Accepted Answer

Parasitic infections often result in an elevated number of eosinophils in the blood. This is because eosinophils play a role in the immune response to parasitic infections. Neutrophils may also be elevated in response to bacterial infections, but the fact that the stool specimen is positive for parasitic eggs suggests a parasitic infection is the cause of the diarrhea. T and B lymphocytes may also be involved in the immune response to parasites, but eosinophils are the most likely to be elevated. Monocytes are not typically elevated in response to parasitic infections.

Question 11

Which of the following is true regarding white blood cells?&#10;A)Granulocytes released from the bone marrow usually spend 10 to 20 days in the blood before entering the interstitial tissues&#10;B)Granulocytes are normally formed only in the bone marrow&#10;C)There are more granulocytes in the bone marrow than in the entire circulation&#10;D)The concentration of neutrophils in the blood is half the concentration of lymphocytes

Accepted Answer

The answer of Which of the following is true regarding...

Deck 34: Resistance of the Body to Infection: I Leukocytes, Granulocytes, the Monocyte-Macrophage System, and Inflammation