Vomitting is not usually caused by:

Correct Answer: B

Rationale: The correct answer is B: Diseases of the inner ear. Vomiting is primarily controlled by the vomiting center in the brainstem, which responds to various stimuli such as irritation of the duodenal mucosa (Choice A), microbial toxins in the blood (Choice C), and severe exercise (Choice D). Diseases of the inner ear do not directly trigger the vomiting reflex, making Choice B the correct answer.

Correct Answer: B

Rationale: Certainly! The correct answer is B: Cholecystokinin (CCK) stimulates the contraction of the gallbladder. This hormone is released from the duodenum in response to the presence of fats and proteins in the small intestine. Its main function is to signal the gallbladder to contract and release bile into the duodenum to aid in the digestion and absorption of fats. A: CCK is not secreted from the jejunum but from the duodenum. C: CCK does not inhibit stomach motility; instead, it enhances the release of digestive enzymes and bile. In summary, choice B is correct as it accurately reflects the role of CCK in stimulating gallbladder contraction, while choices A and C are incorrect based on the functions of CCK in the digestive system.

Correct Answer: C

Rationale: The correct answer is C because saliva does not help in dental caries by increasing acidity; in fact, saliva helps neutralize acids and remineralize teeth. A: Saliva does help in articulation by lubricating the mouth. B: Saliva helps in swallowing by moistening food. D: Saliva contains lysozymes that kill microorganisms, aiding in oral hygiene.

Correct Answer: B

Rationale: The correct answer is B: Serosa. The serosa is the outermost layer of an organ lying within a body cavity. It is composed of connective tissue covered by a layer of mesothelium. This layer is farthest away from the inner core or lumen of the organ. The muscularis externa (choice A) is the layer of muscle tissue located just beneath the serosa. The mucosa (choice C) is the innermost layer of the organ, lining the lumen. The myenteric plexus (choice D) is a network of nerve fibers located between the circular and longitudinal layers of the muscularis externa, playing a role in regulating gastrointestinal motility.

Correct Answer: D

Rationale: The final product of carbohydrate digestion in the small intestine is glucose. Carbohydrates are broken down into simple sugars like glucose during digestion. Enzymes in the small intestine, such as amylase, break down complex carbohydrates into glucose molecules, which can then be absorbed into the bloodstream for energy. Fatty acids (A) are the final product of lipid digestion, while amino acids (B) are the final product of protein digestion. Choice C is irrelevant. In summary, glucose is the correct answer as it is the end product of carbohydrate digestion, while the other choices are related to different types of digestion products.