If the submandibular salivary gland stops functioning:

Correct Answer: B

Rationale: The correct answer is B because the submandibular salivary gland is responsible for producing around 70-75% of total saliva, including amylase. If it stops functioning, there would be a severe deficiency of amylase, leading to impaired digestion of starches. Choice A is incorrect because the reduction in salivary secretion would be more significant than 20%. Choice D is incorrect as mucins are produced by other salivary glands and not solely by the submandibular gland.

Correct Answer: A

Rationale: The correct answer is A: anemia. Carcinoma of the cecum or right colon often presents with chronic blood loss, leading to iron deficiency anemia. This is due to the longer transit time in the right colon allowing for more time for blood to be lost and for the iron in the blood to be absorbed. Choices B, C, and D are less characteristic of carcinoma of the cecum or right colon. Polyposis is more commonly associated with familial adenomatous polyposis, bowel obstruction is more common in advanced stages regardless of location, and diarrhea is more commonly seen in rectal carcinomas due to irritation of the rectal mucosa.

Correct Answer: C

Rationale: Rationale for Correct Answer C: Obstructive jaundice is caused by blockage in the bile ducts, leading to decreased excretion of bilirubin into the intestine. This results in dark stool due to excess stercobilin, a byproduct of bilirubin breakdown. Other choices are incorrect because: A: Fragile red blood cells cause hemolytic jaundice, not obstructive jaundice. B: Elevated blood hemobilirubin is seen in hemolytic jaundice, not obstructive jaundice. D: Dark brown urine is associated with conditions like hemoglobinuria, not obstructive jaundice.

Correct Answer: D

Rationale: The correct answer is D: Muscularis Mucosa. This layer is responsible for primary digestive motility due to its smooth muscle fibers that contract to move food along the digestive tract. The other choices do not directly contribute to motility. A: Mucosa is the innermost layer involved in absorption. B: Submucosa provides support and contains blood vessels. C: Mesentery is a connective tissue that supports and attaches organs, but does not directly regulate motility.

Correct Answer: D

Rationale: The correct answer is D: Hydrochloric acid. Saliva is composed mainly of water, amylase (an enzyme that breaks down starch), and mucus. Hydrochloric acid is not a component of saliva; instead, it is a component of gastric juice produced in the stomach. It plays a role in the digestion of food in the stomach by lowering the pH level. Therefore, choice D is the correct answer as it does not belong to the components of saliva. Choices A, B, and C are incorrect as they are all components found in saliva.