Functions in the liver include production of:

Correct Answer: A

Rationale: The correct answer is A: Digestive enzymes. The liver produces bile, which contains bile salts that help digest fats in the small intestine. Additionally, the liver produces various digestive enzymes like lipase, amylase, and proteases. These enzymes aid in breaking down carbohydrates, proteins, and fats during the digestion process. Choices B, C, and D are incorrect because secondary bile acids are produced in the intestine, stercobilinogen is a product of bilirubin breakdown in the intestine, and CCK (cholecystokinin) is a hormone produced by the small intestine to stimulate the release of bile and pancreatic enzymes but not directly produced by the liver.

Correct Answer: B

Rationale: The correct answer is B: pseudomembranous enterocolitis. Mucosal necrosis is a key characteristic of pseudomembranous enterocolitis, a condition caused by Clostridium difficile infection. The bacteria release toxins that lead to inflammation and damage to the mucosal lining of the intestines, resulting in mucosal necrosis. Blind loop syndrome (choice A) does not specifically involve mucosal necrosis, while pseudomembranous enterocolitis (choice B) does. Choice C is incorrect because only pseudomembranous enterocolitis involves mucosal necrosis. Choice D is incorrect as pseudomembranous enterocolitis does involve mucosal necrosis.

Correct Answer: D

Rationale: The correct answer is D because the stomach secretes intrinsic factor, which is essential for vitamin B12 absorption in the small intestine. This is crucial for preventing vitamin B12 deficiency and maintaining neurological health. The other choices are incorrect because A is partially true but not the main function of the stomach, B is false as total vagus nerve cut decreases stomach secretion, and C is false as the stomach pH varies from acidic (around 1.5-3.5) depending on food intake.

Correct Answer: C

Rationale: The correct answer is C because dysphagia, which is difficulty swallowing, can be caused by various factors such as neurological disorders affecting the swallowing reflex or physical obstructions in the esophagus. This is a key point in understanding the causes of swallowing difficulties. Choice A is incorrect because the pharyngeal phase of swallowing is actually involuntary, not voluntary. Choice B is incorrect as the lower esophageal sphincter (LES) is normally closed to prevent acid reflux and only opens during swallowing. Choice D is incorrect because in the esophageal stage of swallowing, both liquid and solid boluses travel through the esophagus by peristalsis, not just liquid boluses.

Correct Answer: A

Rationale: The correct answer is A because parietal cells secrete hydrogen ions and chloride ions into the lumen, which combine to form hydrochloric acid, maintaining the acidic pH of the stomach essential for digestion. Option B is incorrect as alkaline mucous is produced by goblet cells, not parietal cells. Option C is incorrect as histamine is secreted by enterochromaffin-like cells, not parietal cells. Option D is incorrect as gastric lipase is primarily secreted by chief cells in the stomach.