HESI A2 Anatomy and Physiology 2023

Correct Answer: B

Rationale: The correct answer is B: Glomerulus. The glomerulus is a network of tiny blood vessels in the nephron that filters blood to form urine. It acts as the initial filtration site in the kidney, allowing waste products and excess substances to be removed from the blood. Bowman's capsule surrounds the glomerulus and collects the filtered fluid. The loop of Henle is responsible for reabsorbing water and electrolytes. While the nephron is the functional unit of the kidney, the glomerulus specifically performs the blood filtering process crucial for urine formation.

Correct Answer: B

Rationale: The correct answer is B: Thyroxine. Thyroxine, produced by the thyroid gland, plays a key role in regulating metabolism by controlling the body's metabolic rate. It influences how fast or slow our cells use energy. Insulin (A) regulates blood sugar levels, not metabolism. Glucagon (C) raises blood sugar levels. Cortisol (D) is a stress hormone that affects various body functions but is not primarily responsible for regulating metabolism. Thyroxine is crucial for maintaining overall metabolic balance in the body.

Correct Answer: B

Rationale: The correct answer is B: Ball and socket joint. This type of joint allows for movement in multiple directions due to its structure where a rounded end of one bone fits into a cup-like socket of another bone. This design enables flexion, extension, abduction, adduction, and rotation. Other choices are incorrect because: A: Hinge joint allows movement in one plane only. C: Pivot joint allows rotational movement around a single axis. D: Saddle joint allows for movement in two planes but not as freely as a ball and socket joint.

Correct Answer: A

Rationale: The correct answer is A: Nucleus. The genetic material, DNA, is located within the nucleus of a cell. This is where the DNA is stored and protected. The nucleus also houses the nucleolus, which is responsible for producing ribosomes. Mitochondria (B) is responsible for energy production, not genetic material storage. Ribosomes (C) are involved in protein synthesis, not DNA storage. Golgi apparatus (D) is responsible for packaging and processing proteins, not housing genetic material.

Correct Answer: A

Rationale: The correct answer is A: Cochlea. The cochlea is responsible for detecting sound as it contains hair cells that convert sound vibrations into electrical signals sent to the brain. The Eustachian tube helps equalize pressure, the ossicles transmit sound waves to the cochlea, and the semicircular canals are responsible for balance and spatial orientation. Choose A because the cochlea is specifically designed for detecting sound through its intricate inner workings.