What is the primary function of the adrenal glands?

Correct Answer: B

Rationale: The primary function of the adrenal glands is to regulate metabolism and the body's stress response. The adrenal glands produce hormones like cortisol and adrenaline that play a vital role in managing metabolism, immune response, and stress levels. Choice A is incorrect because insulin is produced by the pancreas, not the adrenal glands. Choice C is incorrect because fighting infections is primarily the role of the immune system. Choice D is incorrect as the regulation of blood pressure involves organs like the heart, kidneys, and blood vessels, not the adrenal glands.

Correct Answer: C

Rationale: The main function of the lymphatic system is to fight infections. It achieves this by filtering lymph, returning excess tissue fluid to the bloodstream, and aiding in the body's immune response. The lymphatic system is crucial in protecting the body against pathogens and maintaining overall health. Choices A, B, and D are incorrect because transporting oxygen, producing hormones, and transporting nutrients are functions performed by other systems in the body, like the respiratory, endocrine, and circulatory systems, respectively.

Correct Answer: A

Rationale: The correct answer is ADH (antidiuretic hormone), also known as vasopressin. ADH helps regulate water balance in the body by controlling the amount of water reabsorbed by the kidneys. When there is a need to conserve water, ADH levels increase, leading to more water reabsorption and concentration of urine. Insulin is involved in regulating blood sugar levels, not water balance. Cortisol is a stress hormone that helps regulate metabolism and immune response, not water balance. Thyroxine is a thyroid hormone that regulates metabolism, growth, and development, not water balance.

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: Temporal lobe. The temporal lobe of the brain is primarily responsible for processing auditory information, including sound perception, speech recognition, and language comprehension. Damage to the temporal lobe can lead to difficulties in hearing, understanding spoken language, and recognizing familiar sounds. Choices A, C, and D are incorrect because the frontal lobe is mainly associated with functions such as decision-making and personality, the occipital lobe is primarily responsible for processing visual information, and the parietal lobe is involved in sensory functions and spatial processing, not auditory functioning.

Correct Answer: B

Rationale: The correct answer is the Adrenal gland. The Adrenal glands, situated on top of the kidneys, are responsible for producing adrenaline. Adrenaline is a hormone that prepares the body for the fight-or-flight response during stress. Choice A, the Thyroid gland, is responsible for producing hormones that regulate metabolism, not adrenaline. Choice C, the Pituitary gland, regulates many of the body's functions by producing various hormones but is not responsible for adrenaline production. Choice D, the Pineal gland, produces melatonin, a hormone that regulates sleep-wake cycles, and is not responsible for adrenaline production.

Correct Answer: B

Rationale: The primary function of the kidneys in the urinary system is to filter blood to remove waste products and excess fluids, which are then excreted as urine. Kidneys act as a filtration system, removing waste like urea, excess salts, and toxins. While the kidneys do play a role in regulating blood pressure by secreting renin and maintaining electrolyte balance by adjusting the levels of sodium, potassium, and other ions in the blood, their main and essential function is filtration and waste removal, making choice B the correct answer.

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: 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.