Define the term evolutionary explanatory hypothesis

Question

Define the term evolutionary explanatory hypothesis for the secretion by heart of a hormone which regulates the renal function? Name that hormone?

Answer 1

The renal regulator hormone is secreted by the heart and is the atrial natriuretic factor (or ANF). The ANF raises the excretion of sodium in the nephron tubules causing low resorption of water, more urinary volume, and therefore lowering the blood pressure. Atrial natriuretic factor is secreted whenever there is a raise of the length of heart muscle fibers in response to high blood pressure. ANF is a natural antihypertensive substance. As the health of heart mainly depends on the stability of normal blood pressure, the evolution must have preserved the atrial natriuretic factor to permit information from the heart to be an extra mechanism for the renal control of the blood pressure.