The stomach, small intestine and large intestine are lined by this epithelium.

Correct Answer: C

Rationale: The correct answer is C: simple columnar epithelium. This type of epithelium is found in the stomach, small intestine, and large intestine. Simple columnar epithelium is ideal for absorption and secretion due to its tall, column-like shape and presence of microvilli. It provides a large surface area for nutrient absorption. Simple squamous epithelium (choice A) is thin and is found in areas where filtration or diffusion occurs, like the lungs. Stratified squamous epithelium (choice B) is found in areas subject to mechanical stress, such as the skin. Pseudostratified columnar epithelium (choice D) is typically found in the respiratory tract and has cilia for moving mucus.

Correct Answer: C

Rationale: The correct answer is C because the uvula and soft palate actually move superiorly, not inferiorly, during swallowing to close off the nasopharynx and prevent food or liquid from entering the nasal cavity. A) The larynx raises to prevent food from entering the trachea. B) The epiglottis moves anteriorly to cover the glottis and prevent aspiration. D) The vestibular folds move laterally to help seal off the airway during swallowing.

Correct Answer: C

Rationale: The correct answer is C: mixing waves. Mixing waves are the stomach contractions that help mix the chyme near the periphery of the stomach and move it towards the pyloric sphincter for further digestion. Peristaltic waves (B) are rhythmic contractions that propel food through the digestive system, not specifically in the stomach. The pyloric pump (A) is not a recognized term in gastrointestinal physiology. Mass movements (D) refer to contractions in the large intestine that move feces towards the rectum, not in the stomach.

Correct Answer: C

Rationale: Rationale: The correct answer is C: urea. Ammonia is toxic and needs to be converted into a less toxic form for excretion. The liver combines ammonia with carbon dioxide to form urea through the urea cycle. Urea is water-soluble and is excreted by the kidneys in urine. Cholesterol (A) is a lipid molecule, bilirubin (B) is a by-product of heme metabolism, and uric acid (D) is a by-product of purine metabolism. These molecules are not formed from the combination of ammonia and carbon dioxide and are not excreted in the kidneys.

Correct Answer: A

Rationale: The correct answer is A: lactose intolerance. This is due to the inability to digest lactose, the sugar found in dairy products, leading to symptoms like intestinal cramps, bloating, and diarrhea. This is a common condition caused by a deficiency of lactase enzyme. Choice B: Diabetes mellitus, Type I, is incorrect as it is an autoimmune condition affecting insulin production, not digestion of dairy products. Choice C: Heartburn is incorrect as it is a symptom of acid reflux, not related to dairy product intolerance. Choice D: Peritonitis is incorrect as it is an inflammation of the abdominal lining, usually caused by infection or injury, not related to dairy product intolerance.