ATI Anatomy and Physiology

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.

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: C

Rationale: The correct answer is C: Store and concentrate bile, a fluid produced by the liver that helps with fat digestion. The gallbladder stores bile produced by the liver and releases it to aid in the digestion of fats. Choice A is incorrect as the liver, not the gallbladder, filters blood and detoxifies harmful substances. Choice B is incorrect because the production of enzymes primarily occurs in the pancreas, not the gallbladder. Choice D is incorrect as the gallbladder's main role is not to further digest food but to store and release bile.

Correct Answer: D

Rationale: The correct answer is the aortic valve. The aortic valve is located between the left ventricle and the aorta, preventing the backflow of blood into the left ventricle once it has been pumped out during systole. Choice A, pulmonic, is incorrect as it is associated with the right side of the heart. Choice B, mitral, is incorrect as it is the valve between the left atrium and ventricle. Choice C, tricuspid, is incorrect as it is located between the right atrium and ventricle.

Correct Answer: C

Rationale: Ovulation is the release of a mature egg (ovum) from the Graafian follicle in the ovary. This process is essential for fertilization. Choice A is incorrect because the fallopian tube does not move the ovum to the uterus; rather, it provides a pathway for the egg to travel from the ovary to the uterus. Choice B is incorrect as the oocyte undergoes its first meiotic division after ovulation. Choice D is incorrect because the corpus luteum forms after ovulation and is responsible for producing progesterone.