HESI A2 Anatomy and Physiology Quizlet

Correct Answer: B

Rationale: The correct answer is B: To fight infection. White blood cells are part of the immune system and play a crucial role in defending the body against infections by attacking and destroying pathogens such as bacteria, viruses, and other foreign invaders. They are key players in the immune response. A: White blood cells do not carry oxygen to the cells. That is the role of red blood cells. C: White blood cells do not transport nutrients. Nutrients are transported by the bloodstream and absorbed by various organs. D: White blood cells are not responsible for clotting blood. Platelets are primarily responsible for blood clotting.

Correct Answer: A

Rationale: The correct answer is A: Hippocampus. The hippocampus is involved in memory formation as it plays a crucial role in the consolidation of short-term memory into long-term memory. It also helps in spatial navigation and declarative memory. The amygdala (choice B) is associated with emotions and emotional memories, not memory formation. The cerebellum (choice C) is primarily responsible for motor coordination, not memory. The medulla oblongata (choice D) is involved in vital autonomic functions like breathing and heart rate, not memory.

Correct Answer: A

Rationale: The correct answer is A: Parathyroid gland. During stress, the hypothalamus signals the pituitary gland to release ACTH, which then stimulates the adrenal cortex to release stress hormones like cortisol. The posterior pituitary releases oxytocin and vasopressin, not directly related to stress. The parathyroid gland regulates calcium levels, not involved in the stress response.

Correct Answer: A

Rationale: The correct answer is A: Insulin. The pancreas produces insulin, a hormone that helps regulate blood sugar levels by facilitating the uptake of glucose into cells. Insulin is crucial in maintaining normal blood sugar levels. Glucagon (choice B) is also produced by the pancreas, but it works in the opposite way to insulin by increasing blood sugar levels. Somatostatin (choice C) is produced by the pancreas and has various functions, including inhibiting the release of insulin and glucagon. Cortisol (choice D) is produced by the adrenal glands, not the pancreas, and plays a role in stress response and metabolism.

Correct Answer: B

Rationale: The correct answer is B: Pivot joint. In the neck, the pivot joint allows for rotational movement by articulating the first and second cervical vertebrae. This joint structure enables the head to rotate from side to side. A: Hinge joint is incorrect because it allows movement in only one plane, like the elbow or knee. C: Ball and socket joint allows for a wide range of motion in multiple directions, like the hip or shoulder. D: Saddle joint allows for movement in two planes, like the thumb joint. The specific rotational movement in the neck is facilitated by the pivot joint, making it the correct choice.