A person who is 'tongue-tied' can often be treated by surgically cutting the

Correct Answer: C

Rationale: The correct answer is C: frenulum. The frenulum is a band of tissue that restricts the movement of the tongue, causing a person to be 'tongue-tied'. By surgically cutting the frenulum, this restriction is alleviated, allowing for improved tongue mobility and speech. Incorrect choices: A: The uvula is a small, fleshy lobe at the back of the tongue, not related to being 'tongue-tied'. B: The buccinator muscle is involved in chewing and facial expressions, not related to tongue-tie. D: The labium refers to the lips, which are not associated with being 'tongue-tied'.

Correct Answer: B

Rationale: The correct answer is B: gastric phase. This phase is activated by the distension of the stomach, triggering local reflexes and parasympathetic reflexes to stimulate gastric secretions. The cephalic phase (A) is triggered by the sight, smell, or thought of food. The intestinal phase (C) inhibits gastric secretions and motility. The enterogastric phase (D) inhibits gastric motility and secretion when chyme enters the duodenum. Thus, the gastric phase is specifically related to the distension of the stomach, making it the correct answer.

Correct Answer: B

Rationale: The correct answer is B: calcium. The liver stores copper, iron, vitamins A, B12, D, E, and K, and glycogen. Calcium is primarily stored in bones and teeth, not in the liver. The liver's main functions are to regulate blood sugar levels, detoxify the body, produce bile, and store essential nutrients and energy sources. Calcium is mainly stored in the bones and teeth for structural support and plays a crucial role in muscle function, nerve transmission, and blood clotting. Therefore, the liver does not serve as a major storehouse for calcium.

Correct Answer: B

Rationale: The correct answer is B: inhibit the defecation reflex. Stimulation of the internal anal sphincters by the sympathetic nervous system or stimulation of the external anal sphincter by the somatic motor nervous system leads to constriction of the anal sphincters, preventing the passage of feces. This inhibits the defecation reflex by maintaining continence. The other choices are incorrect because: A: Stimulating the anal sphincters does not promote the defecation reflex; it actually inhibits it. C: Mass movements are related to the movement of feces through the large intestine, not directly influenced by anal sphincter stimulation. D: Inhibiting mass movements is not a direct effect of anal sphincter stimulation.

Correct Answer: A

Rationale: The correct answer is A because it accurately states that the products of protein digestion can be absorbed as free amino acids or as di- or tripeptides. This is true as the final breakdown products of proteins, whether they are individual amino acids or smaller peptide chains, can be absorbed through the intestinal wall into the bloodstream. Choice B is incorrect because not all proteins are digested equally in the stomach, and the efficiency of digestion can vary based on factors like protein structure and presence of inhibitors. Choice C is incorrect because chymotrypsin, elastase, and carboxypeptidase A are actually produced and secreted by the pancreas, not the gastric zymogenic cells. Choice D is incorrect because there are more than 14 different amino acid transporters involved in the absorption of digested protein products, not just one. Therefore, choice A is the most correct statement regarding protein digestion and absorption.