Which layer of GI tract forms the innermost lining and continuously secretes mucus?
- A. serosa
- B. muscularis externa
- C. muscularis mucosa
- D. mucosa
Correct Answer: D
Rationale: The mucosa is the innermost layer of the GI tract, lined with epithelial cells that secrete mucus to protect the tract and lubricate food passage.
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The cells of the epithelial lining in the vertebrate stomach are not damaged by HCl because of
- A. Mucus secretion covering the epithelium
- B. Neutralization of HCl by alkaline gastric juice
- C. HCl being dilute
- D. Epithelium being resistant to HCl
Correct Answer: A
Rationale: Mucus secreted by gastric cells forms a protective barrier against HCl, preventing damage to the stomach lining.
Infants' gastric juice contains
- A. Nuclease, pepsinogen, lipase
- B. Maltase, pepsinogen, rennin
- C. Amylase, rennin, pepsinogen
- D. Pepsinogen, lipase, rennin
Correct Answer: D
Rationale: Infants' gastric juice contains pepsinogen, lipase, and rennin to aid in milk digestion.
Digestion of starch starts from the mouth, whereas ...A... is the site of digestion mainly for ...B... Choose the correct combination of options to complete the given statement.
- A. A-Stomach; B-Protein
- B. A-Stomach; B-Starch
- C. A-Small intestine; B-Protein
- D. A-Small intestine; B-Cellulose
Correct Answer: C
Rationale: The small intestine is the primary site for protein digestion, while starch digestion begins in the mouth.
Match: Disaccharide
- A. a sugar composed of two monosaccharides
- B. stored form of energy
- C. used in DNA synthesis
- D. component of cell membranes
Correct Answer: A
Rationale: Disaccharides, like sucrose, consist of two monosaccharides linked together and are broken down into simpler sugars during digestion.
All about hepatocyte is true EXCEPT:
- A. Has 3 types of borders
- B. May be binucleated
- C. Secrete bile
- D. Has long microvilli forming brush border
Correct Answer: D
Rationale: Hepatocytes have microvilli facing the space of Disse, but not a brush border, which is characteristic of intestinal enterocytes.