HESI A2 Anatomy and Physiology 2023

Correct Answer: B

Rationale: B: Vitamin B12 is essential for the formation of red blood cells as it plays a key role in the production of red blood cells in the bone marrow. It is necessary for the proper development and maintenance of red blood cells, which carry oxygen throughout the body. Vitamin A supports vision and immune function, not red blood cell formation. Vitamin C aids in collagen formation and immune function. Vitamin D helps in calcium absorption and bone health. Therefore, B is the correct choice for red blood cell formation.

Correct Answer: B

Rationale: The correct answer is B: White blood cells. White blood cells, also known as leukocytes, are primarily responsible for fighting infections by detecting and destroying pathogens. Red blood cells (A) carry oxygen, platelets (C) aid in blood clotting, and plasma (D) is the liquid component of blood carrying nutrients and waste. White blood cells play a crucial role in the immune system's defense against infections, making them the correct choice.

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: 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: C

Rationale: The correct answer is C: Front portion of the parietal lobe. This area is known as the primary motor cortex, responsible for planning, control, and execution of voluntary movements. It receives input from other brain regions involved in movement. Choices A, B, and D are incorrect because the top, middle portion of the parietal lobe is involved in sensory processing, the back of the head is associated with the occipital lobe responsible for vision, and around the auditory cortex is involved in processing auditory information, respectively.