Anatomy and Physiology Hesi A2 Practice Test

Correct Answer: A

Rationale: The correct answer is A: To filter blood and remove old red blood cells. The spleen acts as a blood filter, removing old or damaged red blood cells and recycling their components. This process helps to maintain a healthy balance of red blood cells in the body. The spleen also plays a role in immune function by trapping and removing pathogens from the blood. It does not produce white blood cells (Choice B), store lymphocytes (Choice C), or produce antibodies (Choice D). These functions are typically carried out by other organs in the immune system, such as the bone marrow, lymph nodes, and lymphoid tissues.

Correct Answer: B

Rationale: The correct answer is B: Medulla oblongata. The medulla oblongata is located in the brainstem and is responsible for controlling vital functions such as breathing and heart rate. It contains the respiratory center that regulates breathing and the cardiac center that controls heart rate. The cerebrum (A) is involved in higher brain functions such as thinking and voluntary movements, not in controlling basic bodily functions. The cerebellum (C) is responsible for coordination and balance, not for regulating breathing or heart rate. The hypothalamus (D) plays a role in regulating body temperature, hunger, and thirst, but not specifically in controlling breathing and heart rate.

Correct Answer: B

Rationale: The correct answer is B: Endocrine glands secrete chemicals into the blood. This is because endocrine glands release hormones directly into the bloodstream to regulate various physiological functions throughout the body. Other choices are incorrect: A is incorrect as endocrine glands do not absorb chemicals from the blood; C is incorrect because endocrine glands do not filter chemicals from the blood; and D is incorrect as endocrine glands do not absorb chemicals from the lymphatic system.

Correct Answer: B

Rationale: The correct answer is B because calcium and phosphorus are essential nutrients for bone health. Calcium is a major component of bone structure, while phosphorus helps in bone mineralization. Vitamin D aids in calcium absorption, but does not directly contribute to bone structure. Iron and zinc are important for other bodily functions, not specifically bone health. Magnesium and sodium are not as directly related to bone health as calcium and phosphorus. In summary, calcium and phosphorus directly support bone health, making them the crucial nutrients in this context.

Correct Answer: A

Rationale: The correct answer is A: Cochlea. The cochlea is responsible for hearing as it contains the hair cells that convert sound vibrations into electrical signals sent to the brain. Semicircular canals are responsible for balance, ossicles transmit sound waves, and the Eustachian tube regulates air pressure in the ear. Cochlea is the only structure directly involved in the process of hearing.