Renal Functions, Basic Processes, and Anatomy
Renal corpuscles are located
a. along the corticomedullary border.
b. throughout the cortex.
c. throughout the cortex and outer medulla.
d. throughout the whole kidney.
(b) Renal corpuscles are distributed throughout the cortex, which includes the region just above the corticomedullary border (ie, the juxtamedullary region). None are in the medulla.
Relative to the number of glomeruli, how many loops of Henle, and how many collecting ducts are there?
a. Same number of loops of Henle; same number of collecting ducts.
b. Fewer loops of Henle; fewer collecting ducts.
c. Same number of loops of Henle; fewer collecting ducts.
d. Same number of loops of Henle; more collecting ducts.
(c) Each glomerulus is associated with a nephron, which includes a loop of Henle. Each collecting duct is formed from the coalescence of several nephrons.
It is possible for the body to be in balance for a substance when
a. the amount of the substance in the body is constant.
b. the amount of the substance in the body is higher than normal.
c. the input of the substance into the body is higher than normal.
d. in all of these situations.
(d) Balance implies that input equals output, which can occur at normal or abnormal levels of amounts in the body, or normal or abnormal input, so long as the inputs are matched by equal outputs.
The macula densa is a group of cells located in the wall of
b. the afferent arteriole.
c. the end of the thick ascending limb.
d. the descending thin limb.
(c) The macula densa cells are located in the tubule where it passes between the afferent and efferent arterioles. This location is at the end of the thick ascending limb of the loop of Henle just before it becomes the distal tubule.
The volume of fluid entering the tubules by glomerular filtration in 1 day is typically