HESI A2 Anatomy and Physiology 2023

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: C

Rationale: The motor cortex is located in the front portion of the parietal lobe. This is because it is primarily responsible for planning, executing, and controlling voluntary movements of the body. The parietal lobe is known for processing sensory information, making it an ideal location for integrating sensory inputs with motor commands. Choices A, B, and D are incorrect because the motor cortex is specifically situated in the frontal lobe, not the top or back of the head or around the auditory cortex.

Correct Answer: B

Rationale: The ulnar nerve innervates the arm, specifically the pinky finger, ring finger, and part of the hand. Damage to the ulnar nerve will lead to decreased sensation in these areas. Therefore, the correct answer is B (Arm). The other choices are incorrect because the ulnar nerve does not supply sensation to the Leg (A), Face (C), or Abdomen (D).

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.