HESI A2 Anatomy and Physiology 2023

Correct Answer: B

Rationale: The correct answer is B: cartilage. Cartilage is the substance that makes up the pads between the vertebrae, known as intervertebral discs. Cartilage provides cushioning and support, allowing for flexibility and shock absorption in the spine. Bone (A) is a hard tissue that forms the structure of the vertebrae but does not provide the cushioning function of the discs. Tendon (C) is a fibrous tissue that connects muscle to bone and does not play a role in supporting the vertebrae. Fat (D) is a type of adipose tissue that is not found in the pads between the vertebrae.

Correct Answer: C

Rationale: The correct answer is C: Thyroid gland. The thyroid gland secretes hormones that regulate metabolism and calcium levels in the body. It produces thyroxine (T4) and triiodothyronine (T3) which control the body's metabolic rate. This gland also plays a crucial role in maintaining calcium levels in the blood. The other choices, A: Pituitary gland, B: Adrenal gland, and D: Pineal gland, do not primarily regulate metabolism and calcium levels in the body. The pituitary gland controls various other hormones, the adrenal gland is responsible for stress response and hormone regulation, and the pineal gland regulates sleep-wake cycles and melatonin production.

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: Pinna. The pinna, also known as the auricle, is the most visible part of the ear located on the outside of the head. It helps collect sound waves and directs them into the ear canal. The other choices are incorrect because: A: Cochlea is a spiral-shaped organ in the inner ear responsible for hearing. C: Ear canal is the tube that connects the outer ear to the eardrum. D: Organ of Corti is a structure in the cochlea that contains sensory cells responsible for hearing.

Correct Answer: A

Rationale: The correct answer is A: Pancreas. The pancreas is responsible for producing insulin, a hormone that helps regulate blood sugar levels. It contains clusters of cells called islets of Langerhans, which specifically produce insulin. The liver (B) is involved in storing glucose and producing bile, not insulin. The gallbladder (C) stores bile produced by the liver and aids in digestion, not insulin production. The kidneys (D) filter blood and regulate fluid balance, but do not produce insulin. Therefore, the pancreas is the organ responsible for insulin production in the body.