The small intestine of a person contains a lower concentration of glucose than is present in the blood. The cells of the villi absorb glucose. By which process is the glucose absorbed?
- A. by active transport against the concentration gradient
- B. by active transport down the concentration gradient
- C. by diffusion against the concentration gradient
- D. by diffusion down the concentration gradient
Correct Answer: A
Rationale: Glucose absorption in the small intestine occurs through active transport, particularly when the concentration of glucose is higher in the blood than in the intestine. This requires energy to move glucose against its concentration gradient.
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If for some reason the parietal cells of the gut epithelium become partially nonfunctional, what is likely to happen?
- A. The pH of stomach will fall abruptly
- B. Steapsin will be more effective
- C. Proteins will not be adequately hydrolysed by pepsin into proteoses and peptones
- D. The pancreatic enzymes and specially the trypsin and lipase will not work efficiently
Correct Answer: C
Rationale: Parietal cells secrete HCl; if nonfunctional, the stomach pH rises, reducing pepsin's protein digestion efficiency.
The greater omentum does not participate in:
- A. secretion of enzymes
- B. support and cushioning of the viscera
- C. storage of lipids
- D. protection against the spread of infection
Correct Answer: A
Rationale: The greater omentum provides structural support, lipid storage, and protection against infection spread, but it does not secrete enzymes.
Surface mucous cells show the following EXCEPT:
- A. Found in the isthmus of the fundic glands.
- B. Contain PAS +ve secretory granules.
- C. Secrete acidic mucous.
- D. Continuous with the covering epith of the stomach
Correct Answer: C
Rationale: Surface mucous cells secrete neutral to alkaline mucus, not acidic mucus, to protect the gastric mucosa.
Which of the following hormones stimulates the production of pancreatic juice and bicarbonate?
- A. Insulin and glucagon
- B. Cholecystokinin and secretin
- C. Gastrin and insulin
- D. Angiotensin and epinephrine
Correct Answer: B
Rationale: Secretin and cholecystokinin stimulate the pancreas to release pancreatic juice and bicarbonate.
Which of the following is a key function of the liver?
- A. Produces bile for fat digestion
- B. Absorbs water
- C. Secretes saliva
- D. Moves food via peristalsis
Correct Answer: A
Rationale: The liver produces bile to emulsify fats, among other functions like detoxification and nutrient metabolism.
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