Cardiovascular System, Blood, and Bone Marrow 253153.A newborn girl presents with a mutation in the erythropoietin recep-
tor gene which leads to primary familial erythrocytosis (familial poly-
cythemia). During the 5th to 9th months of fetal development, the primary
effect was on red blood cell production in which of the following?
a. Liver
b. Yolk sac
c. Spleen
d. Thymus
e. Bone marrow
154.A 64-year-old man presents with splenomegaly, lymphadenopathy,
persistent fever, night sweats, and weight loss. Bone marrow aspiration and
biopsy are scheduled. Which of the following would be the best place to
sample bone marrow?
a. Iliac crest
b. Sternum
c. Scapula
d. Humerus
e. Tibia
155.Organs such as the brain and thymus have a more effective blood-
barrier because their blood capillaries are of which of the following types?
a. Continuous type with few vesicles
b. Fenestrated type with diaphragms
c. Fenestrated type without diaphragms
d. Discontinuous type with diaphragms
e. Discontinuous type without diaphragms
156.A 62-year-old African-American man presents with exercise-induced
angina. His serum cholesterol is 277 mg/dL (normal <200), LDL is 157 (nor-
mal <100), HDL is 43 (normal >35), and triglycerides 170 (normal <150). His
BMI is 34 and his coronary risk ratio is 6.84 (normal <5). On cardiac catheter-
ization there is occlusion of the left anterior descending and the origin of the
right coronary artery. The disease process is initiated by which of the following?
a. Proliferation of smooth muscle cells
b. Formation of an intimal plaque
c. Attraction of platelets to collagen microfibrils
d. Adventitial proliferation
e. Injury to the endothelium