which gland produces hormones that regulate sleep

HESI A2

HESI A2 Practice Test Anatomy and Physiology

1. Which gland produces hormones that regulate sleep?

A. Thyroid gland
B. Pineal gland
C. Adrenal gland
D. Pituitary gland

Correct answer: B

Rationale: The pineal gland secretes melatonin, a hormone that plays a crucial role in regulating the sleep-wake cycle. Melatonin production is influenced by exposure to light, with levels increasing in the evening to promote sleep and decreasing in the morning to signal wakefulness. Choices A, C, and D are incorrect because the thyroid gland primarily regulates metabolism, the adrenal gland produces hormones like adrenaline and cortisol related to stress response, and the pituitary gland controls various functions by releasing different hormones but not specifically related to regulating sleep.

2. Which vitamin is necessary for calcium absorption?

A. Vitamin A
B. Vitamin C
C. Vitamin D
D. Vitamin K

Correct answer: C

Rationale: Vitamin D is essential for the absorption of calcium in the intestines, aiding in the maintenance of strong bones and teeth. It helps regulate calcium and phosphorus levels in the body, supporting bone health and preventing conditions like osteoporosis. Vitamin A (Choice A) is important for vision and immune function, not specifically for calcium absorption. Vitamin C (Choice B) is crucial for collagen synthesis and immune function but is not directly involved in calcium absorption. Vitamin K (Choice D) plays a role in blood clotting and bone health, but it is not primarily responsible for calcium absorption.

3. What is the meaning of endocytosis?

A. The cell engulfs solid particles.
B. The cell engulfs liquid material.
C. The cell expels solid particles.
D. The cell releases liquid material.

Correct answer: A

Rationale: Endocytosis is a cellular process where the cell engulfs and internalizes solid particles by forming vesicles. It is a mechanism used for nutrient uptake, cell signaling, and maintaining cellular homeostasis. Options B, C, and D describe processes that are opposite to endocytosis. Choice B is incorrect because it describes pinocytosis, which is the process of engulfing liquid material. Choice C is incorrect as it describes exocytosis, the process of expelling material from the cell. Choice D is incorrect as it describes the process of releasing liquid material from the cell. Therefore, the correct answer is A.

4. Which parts of the heart are separated by the mitral valve?

A. Left atrium and right atrium
B. Right atrium and right ventricle
C. Left ventricle and right ventricle
D. Left atrium and left ventricle

Correct answer: D

Rationale: The mitral valve, also known as the bicuspid valve, separates the left atrium and the left ventricle of the heart. Its primary function is to prevent the backflow of blood from the left ventricle to the left atrium during the heart's contraction. Therefore, option D, 'Left atrium and left ventricle,' is the correct answer. Choices A, B, and C are incorrect because they do not represent the parts separated by the mitral valve.

5. What is the function of the adrenal glands?

A. To regulate blood sugar
B. To produce hormones
C. To produce red blood cells
D. To filter blood

Correct answer: B

Rationale: The adrenal glands function to produce hormones such as adrenaline and cortisol. These hormones play essential roles in regulating metabolism, immune response, and the body's response to stress. Therefore, the correct answer is that the adrenal glands produce hormones. Choices A, C, and D are incorrect as regulating blood sugar is primarily done by the pancreas, producing red blood cells is the function of the bone marrow, and filtering blood is carried out by the kidneys, not the adrenal glands.