ATI Anatomy and Physiology

Correct Answer: B

Rationale: The correct answer is the Medulla Oblongata. This part of the brain is responsible for regulating essential autonomic functions such as heart rate, respiratory rate, and blood pressure. The Corpus Callosum is responsible for connecting the left and right hemispheres of the brain, not for regulating these vital functions. The Pituitary Glands and Pineal Glands are part of the endocrine system and are not directly involved in regulating heart rate, respiratory rate, and blood pressure.

Correct Answer: D

Rationale: The correct answer is D: Antidiuretic hormone. Antidiuretic hormone (ADH), also known as vasopressin, is produced by the hypothalamus and stored in the posterior pituitary gland. It plays a key role in regulating the body's water balance by controlling the amount of water reabsorbed by the kidneys. Choices A, B, and C are incorrect because Growth hormone is produced by the anterior pituitary gland, Luteinizing hormone is produced by the anterior pituitary gland, and Adrenocorticotropic hormone is produced by the anterior pituitary gland.

Correct Answer: A

Rationale: Weight loss is a common symptom of hyperthyroidism, which is characterized by an excess secretion of thyroid hormone. This increased metabolic rate can lead to weight loss despite normal or increased appetite. Bradycardia (slow heart rate), cold intolerance, and lethargy are more commonly associated with hypothyroidism, where there is an insufficient production of thyroid hormone. Therefore, choices B, C, and D are incorrect in the context of hypersecretion of thyroid hormone.

Correct Answer: A

Rationale: The correct answer is the Distal convoluted tubule (DCT). The DCT is the part of the nephron closest to the collecting duct, where the final adjustments to electrolyte and fluid balance are made. Bowman's Capsule is located at the beginning of the nephron, where filtration of blood occurs. The Afferent Arteriole brings blood to the glomerulus for filtration. The Proximal Convoluted Tubule (PCT) is situated after the Bowman's Capsule and is not the part closest to the collecting duct.

Correct Answer: C

Rationale: Calcium plays an essential role in the clotting of blood by being involved in several steps of the coagulation process. It is necessary for the conversion of prothrombin to thrombin, which is a crucial step in forming blood clots. Sodium, magnesium, and potassium do not directly participate in the clotting cascade and are not associated with the coagulation process. Therefore, the correct answer is calcium.