What is the function of the liver in digestion?

Correct Answer: A

Rationale: The liver's main role in digestion is to produce bile, a substance that aids in the breakdown and absorption of fats in the small intestine. Bile emulsifies fats, helping enzymes break them down into smaller molecules for easier absorption in the digestive tract. Therefore, the correct answer is A: 'To produce bile.' Storing glucose, secreting digestive enzymes, and detoxifying harmful substances are functions of the liver, but they are not primarily related to digestion.

Correct Answer: B

Rationale: The correct answer is B: To absorb nutrients. The small intestine's main role in the digestive system is to absorb nutrients from digested food. It has specialized structures, such as villi and microvilli, that increase its surface area for efficient absorption of nutrients into the bloodstream. Choice A is incorrect because the small intestine does not primarily secrete digestive enzymes; that role is mainly carried out by the pancreas and other digestive organs. Choice C is incorrect because the small intestine primarily absorbs nutrients rather than breaking down food. Choice D is incorrect because the absorption of water primarily occurs in the large intestine, not the small intestine.

Correct Answer: B

Rationale: The hippocampus, located in the temporal lobe, is crucial for memory formation. It plays a vital role in converting short-term memories into long-term memories. Damage to the hippocampus can lead to significant memory deficits, highlighting its importance in the memory process. The cerebellum (Choice A) is primarily involved in coordination and balance, not memory. The brainstem (Choice C) is responsible for basic life functions such as breathing and heart rate, not memory. The frontal lobe (Choice D) is associated with functions like decision-making, problem-solving, and emotions, but not primarily memory formation.

Correct Answer: B

Rationale: The correct answer is B: 'To pump blood throughout the body.' The primary function of the heart in the circulatory system is to pump blood, which carries oxygen and nutrients, throughout the body. Choice A, 'To filter blood,' is incorrect as the heart does not filter blood; that is primarily done by the kidneys. Choice C, 'To absorb oxygen,' is incorrect as the lungs are responsible for oxygen absorption. Choice D, 'To remove carbon dioxide,' is incorrect as the lungs facilitate the removal of carbon dioxide from the body.

Correct Answer: B

Rationale: The correct answer is B: Insulin. Insulin, produced by the pancreas, is the hormone responsible for lowering blood glucose levels. It achieves this by promoting the uptake of glucose into cells, thereby reducing the concentration of glucose in the bloodstream. Choice A, Glucagon, is actually a hormone produced by the pancreas that works to raise blood glucose levels by stimulating the liver to release stored glucose. Choice C, Cortisol, is a hormone produced by the adrenal glands, not the pancreas, and is involved in stress response and regulation of metabolism. Choice D, Melatonin, is a hormone produced by the pineal gland that regulates sleep-wake cycles and is not directly involved in blood glucose level regulation.