The effects of parasympathetic stimulation on the GIT include:

Correct Answer: D

Rationale: The correct answer is D because parasympathetic stimulation causes the contraction of the gall bladder. This is due to the release of acetylcholine which stimulates the gall bladder to contract and release bile into the duodenum to aid in digestion. Choices A, B, and C are incorrect as parasympathetic stimulation does not cause constriction of the pylorus, contraction of the internal anal sphincter, or contraction of the external anal sphincter.

Correct Answer: B

Rationale: Step-by-step rationale for why choice B is correct: 1. Carcinoid tumors can produce systemic symptoms due to the release of bioactive substances. 2. Metastasis to the liver can lead to the production of systemic symptoms like flushing and diarrhea. 3. This systemic symptom production is a characteristic feature of carcinoid tumors. 4. Choice B accurately describes the biologic nature of carcinoid tumors in relation to systemic symptoms. Summary of why other choices are incorrect: A: Carcinoid tumors can be malignant and produce systemic symptoms, so they are not always benign. C: Carcinoid tumors originating in the appendix are typically associated with a more favorable prognosis. D: Jejunal ulceration due to gastrin elaboration is more commonly seen in gastrinomas, not carcinoid tumors.

Correct Answer: C

Rationale: Step-by-step rationale: 1. Saliva is slightly acidic, not alkaline. 2. The secretion of saliva is under both neural and hormonal control. 3. Saliva contains enzymes that digest carbohydrates, not proteins. 4. Therefore, choice C is correct as it provides accurate information about the alkalinity of saliva.

Correct Answer: A

Rationale: The correct answer is A because only the calcium-containing antacid may increase gastric acid secretion. This is because calcium-containing antacids can stimulate the release of gastrin, which in turn increases gastric acid secretion. Choices B, C, and D are incorrect because cimetidine, not a calcium-containing antacid, is the one that can cause an increase in urinary pH, produce a laxative effect, and prevent the rise in gastric pH after a meal, respectively. Therefore, A is the only statement that accurately distinguishes between cimetidine and a calcium-containing antacid in the context of treating peptic ulcers.

Correct Answer: D

Rationale: The correct answer is D: Colon. The colon is not a part of the small intestine; it is part of the large intestine. The small intestine consists of three parts: the duodenum, jejunum, and ileum. The duodenum is the first segment of the small intestine, followed by the jejunum and then the ileum. The colon, also known as the large intestine, comes after the small intestine in the digestive system. Therefore, the colon is not a part of the small intestine, making choice D the correct answer.