Question

the sympathetic nervous system and adrenal epinephrine cause ______ of the afferent arterioles, thereby reducing the glomerular filtration rate.

Answer 1

Epinephrine and norepinephrine cause vasoconstriction of the afferent arterioles, reducing the glomerular filtration rate (GFR) in the kidney.

Step-by-step explanation:

Epinephrine and norepinephrine, released by the adrenal medulla and sympathetic nervous system respectively, cause vasoconstriction of the afferent arterioles. This results in a reduction of glomerular filtration rate (GFR). When the frequency of action potentials increases, the arteriolar smooth muscles constrict, leading to diminished glomerular flow and less filtration. Under conditions of stress, the sympathetic nervous activity increases, resulting in vasoconstriction of the afferent arterioles. Additionally, the release of epinephrine from the adrenal medulla causes generalized vasoconstriction, further reducing the blood flow through the kidneys and GFR.

Answer 2

The sympathetic nervous system and adrenal epinephrine cause vasoconstriction of the afferent arterioles, thus reducing the glomerular filtration rate in the kidneys.

Step-by-step explanation:

The sympathetic nervous system and adrenal epinephrine cause vasoconstriction of the afferent arterioles, thereby reducing the glomerular filtration rate (GFR). The kidneys are regulated by the sympathetic nervous system, which can induce vasoconstriction in response to stress or low blood pressure. This vasoconstriction is mediated by the neurotransmitter norepinephrine and the hormone epinephrine (adrenaline), leading to a decrease in blood flow and filtration through the kidneys. When the sympathetic nervous system is activated, it can also stimulate the release of renin, which further contributes to the reduction in GFR by increasing the production of angiotensin II, a potent vasoconstrictor that raises systemic blood pressure and decreases renal blood flow.