Where does chemical digestion of carbohydrates begin?

Correct Answer: A

Rationale: The correct answer is A: Mouth. In the mouth, salivary amylase is secreted, which starts breaking down carbohydrates into simpler sugars like maltose. This initial breakdown of carbohydrates through the enzyme amylase marks the beginning of chemical digestion. The stomach primarily digests proteins, not carbohydrates (eliminating option B). The small intestine is where most of the carbohydrate digestion and absorption occurs, but the process begins in the mouth (eliminating option C). The large intestine is responsible for absorbing water and electrolytes, not carbohydrate digestion (eliminating option D).

Correct Answer: B

Rationale: The correct answer is B: Failure of digestion and absorption of proteins. Atrophy of gastric mucosal glands leads to decreased production of hydrochloric acid and pepsin, essential for protein digestion. This results in impaired breakdown of proteins, leading to failure of digestion and absorption. Choice A is incorrect as starch digestion primarily occurs in the mouth and small intestine. Choice C is incorrect because high gastrin levels are associated with increased acid production. Choice D is incorrect as secretin is not directly involved in protein digestion.

Correct Answer: A

Rationale: The correct answer is A: pyloric stenosis. In pyloric stenosis, there is hypertrophy of the pyloric sphincter muscle, leading to gastric outlet obstruction and projectile vomiting. This typically presents in infants around 2-6 weeks of age. Other choices (B) esophageal atresia presents with difficulty feeding and choking, (C) annular pancreas with duodenal obstruction, and (D) incomplete rotation of the gut with volvulus or obstruction due to malrotation. Pyloric stenosis is the most likely diagnosis in this scenario based on the age of the infant and the symptom of projectile vomiting.

Correct Answer: B

Rationale: The correct answer is B, stomach. Ovarian metastases from gastric carcinoma are commonly bilateral due to the close anatomical relationship between the stomach and ovaries. Stomach cancer frequently spreads to the ovaries through direct extension or lymphatic dissemination. In contrast, esophageal, small intestine, and appendix carcinomas less commonly metastasize to the ovaries, making choices A, C, and D less likely. Thus, the characteristic bilateral ovarian metastases are most commonly associated with carcinoma of the stomach.

Correct Answer: B

Rationale: The correct answer is B: Sleep. During sleep, the body's metabolic rate decreases as it enters a state of rest and recovery. Pregnancy (A) requires increased energy expenditure for fetal development. Males generally have higher metabolic rates than females (C) due to higher muscle mass. Walking (D) requires more energy than resting, leading to a higher metabolic rate. In summary, sleep is the exception as it lowers metabolic rate compared to the other activities listed.