Drug overdosage in parkinsonian patients may cause pronounced gastrointestinal side-effects related to:

Correct Answer: A

Rationale: Bromocriptine's usefulness is severely limited by nausea and vomiting, and this is a problem even in therapeutic doses. Benzhexol and other atropinics may cause dry mouth, gastrooesophageal reflux and constipation. However, the most serious adverse effects for these drugs are neuropsychiatric.

Correct Answer: D

Rationale: Choices A, B, and C are correct: the tongue manipulates food, saliva (with amylase) converts starches to sugars, and it positions food for chewing. D is incorrect because chewing enhances digestion by breaking food into smaller pieces, but 'digestive juices reacting more easily' is vague and not a primary mouth function—digestion continues later with gastric and intestinal juices.

Correct Answer: B

Rationale: The liver stores glycogen , produces bile , and can regenerate , but insulin is made by the pancreas, not the liver, making B correct.

Correct Answer: B

Rationale: The cardiac (lower esophageal) sphincter prevents acid chyme from refluxing into the esophagus, making B correct.

Correct Answer: C

Rationale: Starch digestion begins in the mouth with salivary amylase, making C correct.