Which enzyme is responsible for the digestion of carbohydrates?

Correct Answer: B

Rationale: The correct answer is B: amylase. Amylase is responsible for breaking down carbohydrates into smaller sugar molecules in the digestive system. It is produced in the saliva and pancreas. Lipase (A) digests fats, pepsin (C) digests proteins, and trypsin (D) also digests proteins, not carbohydrates. Therefore, amylase is the correct enzyme for carbohydrate digestion.

Correct Answer: A

Rationale: After a cholecystectomy, the gallbladder is removed, affecting bile storage and release. The liver still produces bile, but it is not stored in the gallbladder for efficient release when needed. This results in inadequate bile availability to emulsify fats, leading to difficulty digesting fat-rich foods. Choices B and C are incorrect as they do not directly address the issue of insufficient bile production. Choice D is incorrect as bile concentration is not the primary concern post-cholecystectomy.

Correct Answer: D

Rationale: The correct answer is D because the oesophageal phase of swallowing starts when a bolus enters the oropharynx. This triggers the swallowing reflex, leading to the contraction of the upper oesophageal sphincter and relaxation of the lower sphincter to allow the bolus to move into the oesophagus. Choices A and B are incorrect because the oesophageal phase can proceed with the mouth open and is not primarily reflex-controlled by the myenteric plexus. Choice C is incorrect as the swallowing center in the brain coordinates and initiates the swallowing reflex but is not the primary control of the oesophageal phase.

Correct Answer: A

Rationale: Step-by-step rationale: 1. Hematemesis refers to vomiting blood, which typically originates from the upper gastrointestinal tract. 2. Blood from the lower gastrointestinal tract is usually passed through the rectum as melena or hematochezia. 3. Therefore, hematemesis is a clear indication of upper gastrointestinal bleeding. 4. Choice A is correct because hematemesis specifically points to upper GI bleeding. Summary: - Choice B is incorrect because lower GI bleeding does not typically present with vomiting blood. - Choice C is incorrect as hematemesis is specific to upper GI bleeding. - Choice D is incorrect as hematemesis indicates an issue in the upper GI tract.

Correct Answer: B

Rationale: The correct answer is B because esophageal carcinoma most frequently involves squamous cell carcinoma, not adenocarcinoma. Male predominance (A), patients over 50 years of age (C), and squamous cell type (D) are all accurate descriptors of esophageal carcinoma. Adenocarcinoma is more commonly associated with the lower esophagus and gastroesophageal junction, not the most frequent type in esophageal carcinoma overall.