What effect does aldosterone secretion have on electrolyte levels?

Correct Answer: B

Rationale: Aldosterone is a hormone that primarily acts on the kidneys to increase the reabsorption of sodium and water into the bloodstream. As a result, sodium levels are increased. Choices A, C, and D are incorrect. Aldosterone does not significantly affect calcium, potassium, or magnesium levels.

Correct Answer: B

Rationale: The correct answer is B: Symphysis pubis. The symphysis pubis is a component of the appendicular skeleton, specifically part of the pelvic girdle. The xiphoid process (Choice A) is part of the axial skeleton, located at the lower end of the sternum. The sacrum (Choice C) is also part of the axial skeleton, forming the posterior part of the pelvis. The sternum (Choice D) is part of the axial skeleton, located in the center of the chest.

Correct Answer: A

Rationale: The correct answer is Type O. Individuals with blood type O can only receive blood from donors with blood type O. This is because type O blood lacks both A and B antigens, so if a person with type O blood receives blood with A, B, or AB antigens, their immune system will recognize these as foreign substances and attack them. Choices B, C, and D are incorrect because individuals with type A can receive blood from A or O donors, individuals with type B can receive blood from B or O donors, and individuals with type AB can receive blood from A, B, AB, or O donors.

Correct Answer: A

Rationale: The correct answer is the Ileum. The Ileum is the final section of the small intestine where the absorption of key nutrients such as iron and bile salts occurs. The Jejunum mainly absorbs nutrients like carbohydrates and proteins, while the Duodenum primarily facilitates the absorption of minerals and vitamins. The Colon's main function is to absorb water and electrolytes, not iron and bile salts. Therefore, choices B, C, and D are incorrect.

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: B

Rationale: The correct function associated with the dermal layer of the skin is to provide support and structure to the skin. The dermis is the thickest layer of the skin and is responsible for maintaining the skin's integrity and firmness. Choices A, C, and D are incorrect as sensory perception, protection from UV rays, and insulation are functions associated with other layers of the skin, such as the epidermis and subcutaneous tissue.

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.

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.