HESI A2 Anatomy and Physiology Quizlet

Correct Answer: B

Rationale: The correct answer is B: Pivot joint. Pivot joints allow for rotational movement around a single axis. This type of joint is found in the neck, allowing the head to rotate side to side. Hinge joints (choice A) allow movement in one plane like the elbow. Ball and socket joints (choice C) allow for a wide range of movement in multiple directions like the hip and shoulder. Saddle joints (choice D) allow for movement in two axes like the thumb. Therefore, the correct answer is pivot joint as it specifically allows for rotational movement around a single axis.

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 main function of the circulatory system is to transport oxygen and nutrients to all cells in the body. This is achieved through the blood vessels and the pumping action of the heart. Oxygen is necessary for cellular respiration, while nutrients are essential for cell growth and metabolism. Without these, cells cannot function properly, leading to organ failure and ultimately, death. Options B, C, and D are incorrect because although the circulatory system indirectly helps remove waste products, regulate body temperature, and protect organs, these are not its primary functions.

Correct Answer: B

Rationale: The correct answer is B: Adrenaline. The adrenal medulla is part of the adrenal glands and is responsible for producing adrenaline, also known as epinephrine. Adrenaline is a hormone that plays a crucial role in the body's fight or flight response, increasing heart rate, blood flow to muscles, and overall alertness in response to stress or danger. Insulin (A) is produced by the pancreas to regulate blood sugar levels, cortisol (C) is produced by the adrenal cortex to regulate stress response and metabolism, and melatonin (D) is produced by the pineal gland to regulate sleep-wake cycles.

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.