Which of the following organs has 3 layers of smooth muscle in its muscularis externa?

Correct Answer: C

Rationale: The correct answer is C: stomach. The stomach has 3 layers of smooth muscle in its muscularis externa, which help in mixing and churning food for digestion. The small intestine (A) has 2 layers of smooth muscle, the esophagus (B) has skeletal and smooth muscle, and the large intestine (D) has outer longitudinal and inner circular layers of smooth muscle, not 3 distinct layers like the stomach.

Correct Answer: C

Rationale: The correct answer is C: an anticholinergic medication. Anticholinergic medications inhibit the action of acetylcholine, a neurotransmitter responsible for stimulating intestinal motility. By blocking acetylcholine, anticholinergics can effectively immobilize the intestines during surgery. Choice A (a cholinergic medication) would have the opposite effect by stimulating intestinal motility. Choice B (an antiadrenergic medication) is not directly related to immobilizing the intestines. Choice D is incorrect as only option C is the most effective at achieving intestinal immobilization.

Correct Answer: A

Rationale: The correct answer is A: esophagus. The esophagus is a muscular tube that carries food from the mouth to the stomach through a process called peristalsis. It is lined with muscles that contract to push food downward. The trachea (B) is responsible for breathing, not digestion. The nasopharynx (C) is part of the respiratory system. The epiglottis (D) is a flap of tissue that prevents food from entering the trachea during swallowing.

Correct Answer: B

Rationale: The most likely diagnosis for the given presentation is Gastro-oesophageal reflux disease (GERD). The chest pain exacerbated by lying flat and relieved by leaning forward is typical of GERD due to acid reflux when lying down. Angina and myocardial infarction typically present with exertional chest pain, while pulmonary embolism presents with sudden onset pleuritic chest pain often associated with shortness of breath. Therefore, the correct answer is B.

Correct Answer: D

Rationale: The correct answer is D: Right heart failure. The swollen ankles and raised jugular venous pressure are consistent with right heart failure in the setting of chronic obstructive pulmonary disease. In COPD, chronic hypoxia can lead to pulmonary hypertension and subsequent right heart failure. Asthma (choice A) is a reversible airway disease, not associated with right heart failure. Congestive heart failure (choice B) typically presents with features of pulmonary edema, which are absent in this case. Constrictive pericarditis (choice C) can also cause elevated jugular venous pressure, but swollen ankles are not a common feature.