15

75. The probable source of surface active material (surfactant)  coating the alveolar surface is
 

a. goblet cells
b. small alveolar cells (type I orA pneumocytes)
c. great alveolar cells (type II or B pneumocytes)
d. Clara cells
e. septal cells

 
76. The structural/functional unit of the respiratory system is
 

a. a terminal bronchiole and its branches
b. an alveolus
c. a bronchopulmonary segment
d. an alveolar duct and its branches
e. a respiratory bronchiole and its branches

 
77. Smooth endoplasmic reticulum would be expected to be most abundant in
 

a. steroid secreting cells
b. fibroblasts
c. mucous secreting cells
d. serous secreting cells
e. rubriblasts

 
78. A uriniferous tubule (nephron) includes all of the following except
 

a. glomerulus
b. Bowman's capsule
c. juxtaglomerular apparatus
d. basal lamina (basement membrane)
e. podocytes

 
79. Juxtaglomerular cells are modified
 

a. distal tubule cells
b. proximal tubule cells
c. efferent arteriole cells
d. macula densa cells
e. afferent arteriole cells

 
80. The macula densa of the kidney is formed by cells of the

a. afferent arteriole
b. distal convoluted tubule
c. descending thick part of Henle's loop
d. proximal convoluted tubule
e. thin portion of Henle's loop