How can cholesterol absorption be decreased?

Correct Answer: B

Rationale: The correct answer is B: Plant sterols. Plant sterols can reduce cholesterol absorption by competing with cholesterol for absorption sites. Vitamin K, choice A, does not have a significant impact on cholesterol absorption. Trans fats, choice C, are known to increase cholesterol levels rather than decrease absorption. Phospholipids, choice D, play a role in cell structure and are not directly involved in reducing cholesterol absorption.

Correct Answer: C

Rationale: Chylomicrons are the lipoproteins responsible for transporting dietary fat from the intestines to various tissues, including the liver. VLDL carries lipids synthesized in the liver, LDL transports cholesterol to tissues, and HDL helps transport cholesterol away from tissues to the liver for excretion. Therefore, in the context of carrying fat from a meal just consumed to the liver, chylomicrons are the correct choice.

Correct Answer: C

Rationale: The correct answer is C: Small intestine. The majority of lipid digestion occurs in the small intestine, where bile and pancreatic lipase are active. Lipids are broken down into fatty acids and glycerol in the small intestine. Choices A, B, and D are incorrect because the mouth and stomach play minor roles in lipid digestion, and the large intestine is mainly responsible for absorbing water and electrolytes from the indigestible food residues.

Correct Answer: B

Rationale: Cholecystokinin (CCK) is the correct answer. It is the hormone responsible for stimulating the gallbladder to contract and release bile to aid in fat digestion. Gastric lipase (Choice A) is an enzyme that breaks down fats in the stomach, not a hormone involved in gallbladder function. Vitamin D (Choice C) is important for calcium absorption and bone health, but it is not directly related to gallbladder function. Enterokinin (Choice D) is a peptide hormone that affects smooth muscle contractions in the gastrointestinal tract, but it is not specifically responsible for stimulating the gallbladder to release bile.

Correct Answer: A

Rationale: Bile salts are essential for emulsifying fats in the body. They break down fats into smaller droplets, increasing the surface area for enzymes to work on during digestion. Cholecystokinin is a hormone that stimulates the release of bile and pancreatic enzymes, but it is not directly involved in emulsification. Chyme is the semi-fluid mass of partly digested food that moves from the stomach to the small intestine and does not play a role in emulsifying fats. Trypsin is an enzyme produced by the pancreas that acts on proteins, not fats.