HESI A2 Anatomy and Physiology 2023

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: B

Rationale: The correct answer is B: To produce bile and detoxify substances. The liver plays a crucial role in producing bile, which aids in digestion by breaking down fats. It also detoxifies harmful substances in the body. Choices A, C, and D are incorrect because the liver does not primarily filter blood, produce insulin, or produce red blood cells. Filtering blood is mainly done by the kidneys, insulin is produced by the pancreas, and red blood cells are produced in the bone marrow.

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: C

Rationale: The correct answer is C: Pituitary gland. The pituitary gland is known as the 'master gland' because it controls the functions of other endocrine glands in the body by secreting various hormones that regulate growth, metabolism, reproduction, and stress response. It is located at the base of the brain and is divided into anterior and posterior lobes, each with distinct functions. The other choices are incorrect because the thyroid gland regulates metabolism (A), the adrenal gland produces hormones involved in stress response (B), and the pineal gland regulates sleep-wake cycles and melatonin production (D), but none of them have the overarching control over other glands like the pituitary gland does.

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.