HESI A2 Anatomy and Physiology 2023

Correct Answer: B

Rationale: The correct answer is B: Hinge joint. The knee joint is classified as a hinge joint because it primarily allows movement in one plane, similar to a door hinge. This type of joint permits flexion and extension movements, which are the main actions of the knee. The other choices are incorrect because: A: Ball and socket joint allows for multi-directional movement, such as the hip joint. C: Pivot joint allows for rotation around an axis, like the joint between the radius and ulna bones in the forearm. D: Saddle joint allows for movements in two planes, like the joint at the base of the thumb.

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: Support and protection. The skeletal system provides structural support for the body and protects internal organs. It also helps with movement, stores minerals, and produces blood cells. Choices A, C, and D are incorrect because the production of red blood cells occurs in the bone marrow, secretion of hormones is primarily the function of the endocrine system, and regulation of body temperature is controlled by the nervous system and other mechanisms, not the skeletal system.

Correct Answer: A

Rationale: The primary function of the cardiovascular system is to transport oxygen and nutrients to cells throughout the body. This is achieved through the circulation of blood by the heart and blood vessels. Oxygen is vital for cellular respiration, and nutrients are essential for cell function. Regulating body temperature is primarily the role of the integumentary and nervous systems, not the cardiovascular system. Removing waste products is mainly the function of the excretory system. Hormone production is primarily controlled by the endocrine system, not the cardiovascular system. Therefore, choice A is correct as it directly aligns with the main purpose of the cardiovascular system.

Correct Answer: A

Rationale: The correct answer is A: Biceps brachii. The biceps brachii is a muscle located in the upper arm that is responsible for flexing the forearm at the elbow joint. It is a powerful supinator of the forearm and also helps in shoulder flexion. The other choices are incorrect because: B: Triceps brachii is responsible for extending the forearm, not flexing it. C: Deltoid is a shoulder muscle responsible for abduction, not forearm flexion. D: Brachialis is a forearm muscle that assists in elbow flexion but is not the primary muscle involved in flexing the forearm.