Contractions that mix material in the small intestine are called

Correct Answer: D

Rationale: The correct answer is D: segmental contractions. Segmental contractions mix material in the small intestine by contracting and relaxing specific segments of the intestine to mix and move the contents. This process helps with digestion and nutrient absorption. A: Peristalsis refers to the wave-like muscle contractions that propel food through the digestive system, not mixing. B: Deglutition is the process of swallowing food, not mixing it in the small intestine. C: Mass movements are large contractions that move material through the large intestine, not the small intestine where mixing occurs.

Correct Answer: D

Rationale: Rationale: 1. The oropharynx and laryngopharynx are parts of the pharynx involved in the digestive system. 2. The oropharynx receives food from the mouth, while the laryngopharynx leads to the esophagus. 3. The nasopharynx is not involved in food digestion, it connects to the nasal cavity. 4. The laryngopharynx is crucial in guiding food towards the esophagus. Summary: A: Incorrect, as the oropharynx alone does not cover the entire pathway of food. B: Incorrect, as the nasopharynx is not involved in food passage. C: Incorrect, as it excludes the laryngopharynx which is essential for food digestion.

Correct Answer: C

Rationale: Histamine stimulates the parietal cells in the stomach lining to release hydrochloric acid (HCl). This process plays a crucial role in the digestion of food. Parietal cells are responsible for producing stomach acid, which helps break down food and kill bacteria. Choice A is incorrect because intrinsic factor is not released by parietal cells in response to histamine. Choice B is incorrect because pepsinogen is released by chief cells, not parietal cells. Choice D is incorrect because mucous neck cells secrete mucus to protect the stomach lining, but they are not directly stimulated by histamine to release mucus.

Correct Answer: D

Rationale: The correct answer is D: cirrhosis. Jaundice, pale skin, and liver with connective tissue buildup are classic symptoms of cirrhosis - a condition characterized by scarring of the liver due to long-term damage. Jaundice occurs when the liver is unable to properly process bilirubin, leading to yellowing of the skin and eyes. The pale color can be due to anemia often seen in cirrhosis. The buildup of connective tissue is indicative of fibrosis and scarring in the liver. Gastritis (A) is inflammation of the stomach lining, pancreatitis (B) is inflammation of the pancreas, and gallstones (C) are solid particles that form in the gallbladder. These conditions do not typically present with the combination of symptoms described.

Correct Answer: A

Rationale: The correct answer is A: mass movements. Mass movements are strong contractions that occur 3 to 4 times a day, moving large amounts of fecal material through the colon. This process involves the transverse and descending colon, which aligns with the description provided in the question. Mass movements help propel waste towards the rectum for elimination. Choice B, haustral churning, refers to the mixing and propelling actions that occur in the haustra of the colon, not involving large parts of the transverse and descending colon. Choice C, the defecation reflex, is the process that triggers the urge to defecate, not specific contractions involving the colon. Choice D, teniae coli waves, are contractions of the longitudinal muscles of the colon that create the haustra, not the strong propulsive contractions described in the question.