In which of the following segments of the gastrointestinal tract is primary carcinoma least common?

Correct Answer: C

Rationale: The correct answer is C: small intestine. Primary carcinoma is least common in the small intestine due to its relatively lower exposure to carcinogens and slower cellular turnover compared to other segments like the colon. The esophagus is prone to carcinoma due to chronic irritation from acid reflux. The stomach is susceptible due to factors like Helicobacter pylori infection and dietary habits. The colon is at higher risk due to frequent exposure to fecal carcinogens. In summary, the small intestine has the least incidence of primary carcinoma due to lower exposure to risk factors.

Correct Answer: C

Rationale: The correct answer is C because during swallowing, the swallowing center in the medulla oblongata inhibits the medullary respiratory center to prevent aspiration. This coordination ensures that breathing is temporarily halted to prevent food or liquid from entering the airway. Choices A, B, and D are incorrect because not all processes of deglutition are under voluntary control, the vocal folds actually close to protect the airway during swallowing, and the movement of the food bolus down the esophagus is facilitated by peristalsis rather than gravity.

Correct Answer: B

Rationale: The correct answer is B: Break down proteins. Hydrochloric acid in the stomach helps to activate pepsin, an enzyme that breaks down proteins into smaller peptides. This process is essential for proper digestion of proteins. Choice A is incorrect because carbohydrates are broken down by amylase enzymes in the mouth and small intestine. Choice C is incorrect because emulsification of fats occurs in the small intestine with the help of bile. Choice D is incorrect as hydrochloric acid plays a significant role in the digestion of proteins in the stomach.

Correct Answer: A

Rationale: The correct answer is A: a creamy paste called chyme. After food enters the stomach, it gets mixed with gastric juices and enzymes, forming a semi-liquid substance known as chyme. This chyme is then slowly released into the small intestine for further digestion and absorption of nutrients. Option B is incorrect as food is not rolled into a bolus in the stomach but rather churned into chyme. Option C is incorrect as pepsin, an enzyme for protein digestion, is already present in the stomach and starts working on digesting proteins before the food leaves the stomach. Option D is incorrect as chyme is the accurate description of the partially digested food leaving the stomach.

Correct Answer: A

Rationale: The correct answer is A: Administer IV fluids. Initial care for acute diverticulitis involves IV fluids to maintain hydration and electrolyte balance, as patients often have nausea, vomiting, and decreased oral intake. IV fluids help prevent dehydration and support the body during the acute phase of the condition. Options B, C, and D are incorrect. Colonoscopy is contraindicated during acute diverticulitis due to the risk of perforation. High-fiber diet and stool softeners/enemas are not recommended initially as they can worsen symptoms and increase the risk of complications.