Anatomy and Physiology Hesi A2 Practice Test

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.

Correct Answer: B

Rationale: The correct answer is B: Vitamin A. Step 1: Vitamin A is essential for maintaining healthy skin as it promotes cell growth and repair. Step 2: Vitamin A is crucial for vision as it is a component of rhodopsin, a protein in the retina. Step 3: Vitamin C (choice A) is important for immune function and collagen production, not specifically skin or vision. Vitamin D (choice C) is essential for bone health, not skin or vision. Vitamin K (choice D) is important for blood clotting, not skin or vision.

Correct Answer: B

Rationale: The correct answer is B: Adrenaline. Adrenal glands release adrenaline during stress as part of the fight-or-flight response. Adrenaline increases heart rate, blood flow to muscles, and boosts energy. Insulin (A) regulates blood sugar, not stress response. Melatonin (C) regulates sleep-wake cycles. Cortisol (D) is released during stress but is not the primary hormone for immediate stress response like adrenaline.

Correct Answer: B

Rationale: The correct answer is B: Erythropoiesis. Erythropoiesis is the process of producing red blood cells. This process occurs in the bone marrow and is regulated by the hormone erythropoietin. Thrombopoiesis (A) is the production of platelets, not red blood cells. Hematopoiesis (C) is the general process of blood cell formation, including red blood cells, white blood cells, and platelets. Phagocytosis (D) is the process by which cells engulf and digest particles, not related to red blood cell production. Therefore, the correct answer is B as it specifically relates to the production of red blood cells.

Correct Answer: B

Rationale: The correct answer is B: Hyoid. The hyoid bone is the only bone in the human body that does not directly articulate with any other bone. It is a U-shaped bone located in the neck, suspended by ligaments and muscles. Its unique position and function in supporting the tongue and larynx make it distinct from the other choices. The femur (A), radius (C), and tibia (D) are all long bones that articulate with neighboring bones at their respective joints, such as the hip, elbow, and knee joints, respectively. The hyoid bone's isolated location and lack of direct articulation with other bones set it apart as the correct choice.