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 gallbladder's function is to store and concentrate bile produced by the liver. When food is ingested, the gallbladder releases bile into the small intestine to aid in the digestion and absorption of fats. Choice A is incorrect because the liver produces bile. Choice C is incorrect as the liver, not the gallbladder, is responsible for detoxifying harmful substances. Choice D is also incorrect as blood sugar regulation is mainly controlled by the pancreas and hormones like insulin and glucagon.

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.

Correct Answer: A

Rationale: The pituitary gland regulates metabolism by producing and secreting hormones that control various bodily functions. It plays a key role in growth, reproduction, and overall hormone balance. This is supported by its location in the brain, connected to the hypothalamus which controls hormone production. Other choices are incorrect: Bile is produced in the liver, blood filtration is mainly done by the kidneys, and muscle movement is controlled by the nervous system.

Correct Answer: B

Rationale: The correct answer is B: Hinge joint. The elbow joint is a hinge joint because it allows movement in one plane, similar to a door hinge. It primarily allows flexion and extension movements. A ball and socket joint (A) allows a wider range of motion in multiple planes. A pivot joint (C) allows rotation around a central axis. A saddle joint (D) allows movement in multiple directions with a greater range of motion compared to a hinge joint.