The period between the closure of the semilunar valve and the opening of the atrioventricular valves is called:

Correct Answer: C

Rationale: This period is ventricular relaxation (diastole), where semilunar valves close (end of systole) and atrioventricular valves open to allow passive filling, though the term here aligns with relaxation before filling begins.

Correct Answer: B

Rationale: The cardiac plexus includes parasympathetic fibers from the vagus nerve and sympathetic fibers from the sympathetic trunk.

Correct Answer: C

Rationale: Fenestrated capillaries without diaphragms are found in the renal glomerulus for filtration.

Correct Answer: C

Rationale: Angiotensin II causes vasoconstriction and aldosterone release, leading to chronic hypertension.

Correct Answer: B

Rationale: Erythropoietin is secreted by peritubular capillary cells in the kidney in response to hypoxia.