Which of the following statements are true of the internal structure of the kidney? (Read carefully and select all of the correct statements.)
a. The renal pelvis has extensions called calyces to collect urine.
b. The renal artery enters the kidney at the hilus on the lateral side.
c. The outermost tissue layer is the renal medulla, which is made of renal corpuscles.
d. The capillaries of the kidneys are the glomeruli and the peritubular capillaries.
e. Collecting tubules extend to the apex of each renal pyramid.
f. The renal cortex consists of small segments called renal pyramids.
The correct answer and explanation is:
The correct statements are:
- a. The renal pelvis has extensions called calyces to collect urine.
- d. The capillaries of the kidneys are the glomeruli and the peritubular capillaries.
- e. Collecting tubules extend to the apex of each renal pyramid.
Explanation:
- a. The renal pelvis has extensions called calyces to collect urine: The renal pelvis is a funnel-shaped structure that collects urine from the renal calyces. The calyces are extensions of the renal pelvis that collect urine from the renal pyramids, which are made up of collecting tubules.
- d. The capillaries of the kidneys are the glomeruli and the peritubular capillaries: The kidneys have two main capillary networks. The glomerulus is a network of capillaries located in the renal corpuscle, where filtration of blood takes place. The peritubular capillaries surround the tubules and are involved in reabsorption and secretion of substances between the blood and the kidney tubules.
- e. Collecting tubules extend to the apex of each renal pyramid: The collecting tubules are responsible for collecting urine from the nephrons. They extend through the renal cortex and into the renal medulla, where they empty into the renal papillae at the apex of each renal pyramid, eventually draining into the calyces.
Incorrect statements:
- b. The renal artery enters the kidney at the hilus on the lateral side: The renal artery enters the kidney at the hilus, but it does not specifically enter on the “lateral” side. The hilus is located on the medial side of the kidney, where structures like the renal artery, renal vein, and ureter enter and exit.
- c. The outermost tissue layer is the renal medulla, which is made of renal corpuscles: This is incorrect. The renal cortex is the outermost layer of the kidney, not the renal medulla. The renal medulla is deeper and contains the renal pyramids, but it does not contain renal corpuscles.
- f. The renal cortex consists of small segments called renal pyramids: This is incorrect. The renal cortex does not consist of renal pyramids. The renal pyramids are located in the renal medulla, not the cortex. The cortex contains the renal corpuscles and parts of the nephrons.