Question

23 multiple choice 2 points
chyme is:
a hormone that stimulates stomach acid production.
partially digested food mixed with gastric juices.
a protein produced by the small intestine.
a digestive enzyme produced in the stomach.

24 multiple choice 2 points
which is the primary function of the proximal convoluted tubule (pct)?
glucose secretion
urea excretion
sodium reabsorption
filtrate formation

Explanation:

Define chyme and evaluate options for Question 23

Chyme is the semi-fluid mass of partially digested food and gastric juices that is expelled by the stomach into the duodenum.

• Option 1 is incorrect (gastrin is the hormone).
• Option 2 is correct (partially digested food mixed with gastric juices).
• Option 3 is incorrect (chyme is not a protein).
• Option 4 is incorrect (chyme is a mixture, not a single enzyme).

Identify the primary function of the PCT for Question 24

The proximal convoluted tubule (PCT) is responsible for the reabsorption of the majority of water, essential ions, and organic nutrients (like glucose and amino acids) from the glomerular filtrate back into the blood.

• Option 1 is incorrect (glucose is reabsorbed, not secreted).
• Option 2 is incorrect (urea excretion is not the primary active function of the PCT).
• Option 3 is correct (sodium reabsorption is a primary active transport process driving most other reabsorption in the PCT).
• Option 4 is incorrect (filtrate formation occurs in the renal corpuscle/glomerulus).

Answer:

Question 23

• a hormone that stimulates stomach acid production.
• partially digested food mixed with gastric juices. (Correct answer)
• a protein produced by the small intestine.
• a digestive enzyme produced in the stomach.

Question 24

• glucose secretion
• urea excretion
• sodium reabsorption (Correct answer)
• filtrate formation