What causes the afferent arteriole to dilate?

What causes the afferent arteriole to dilate?

A reduction in renal perfusion normally results in dilatation of the afferent glomerular arteriole and constriction of the efferent arteriole so that glomerular filtration rate (GFR) is kept constant.

What constricts the afferent arteriole?

ATP and adenosine act locally as paracrine factors to stimulate the myogenic juxtaglomerular cells of the afferent arteriole to constrict, slowing blood flow and reducing GFR.

How does sympathetic nervous system affect glomerular filtration rate?

Renal sympathetic nerve stimulation produces a frequency-dependent decrease in single-nephron glomerular filtration rate that is due to a combination of increases in both afferent and efferent glomerular arteriolar resistance and a decrease in glomerular capillary hydrostatic pressure gradient and glomerular capillary …

How does sympathetic activity affect GFR?

Fibers of the Sympathetic Nervous System innervate the kidneys and along with circulating catecholamines enhance tubular sodium and water resorption while reducing Glomerular Filtration Rate (GFR) and total Renal Blood Flow (RBF).

What is the function of afferent arteriole?

The afferent arteriole is an arteriole that feeds blood into the glomerulus. The renal arterioles play a central role in determining glomerular hydraulic pressure, which facilitates glomerular filtration.

What is the function of the afferent arteriole quizlet?

specialized structure formed by the distal convoluted tubule and the glomerular afferent arteriole. It is located near the vascular pole of the glomerulus and its main function is to regulate blood pressure and the filtration rate of the glomerulus.

What causes the constriction of afferent arterioles quizlet?

Increased Blood Pressure leads to afferent arteriole vasoconstriction and efferent arteriole vasodilation. This leads to a decrease in glomerular hydrostatic pressure and therefore decrease in GFR. Decreased Blood Pressure leads to afferent arteriole vasodilation and efferent arteriole vasoconstriction.

How does the parasympathetic nervous system affect the liver?

The parasympathetic nerves branch off the vagus nerve, and are thought to innervate the liver either directly as preganglionic fibers originating in the dorsal motor nucleus of the brainstem, or synapse on ganglia located at the hepatic hilus and within the hilar spaces (27, 59, 104).

What is the role of sympathetic nervous system?

sympathetic nervous system, division of the nervous system that functions to produce localized adjustments (such as sweating as a response to an increase in temperature) and reflex adjustments of the cardiovascular system.

What are the functions of sympathetic nerves?

The sympathetic nervous system connects the internal organs to the brain by spinal nerves. When stimulated, these nerves prepare the organism for stress by increasing the heart rate, increasing blood flow to the muscles, and decreasing blood flow to the skin.

How does changing the afferent and efferent Arteriole affect GFR?

An increase in the afferent arteriolar diameter (decrease in resistance) causes an increase in the glomerular capillary hydrostatic pressure and an increase in GFR. A decrease in the diameter of the efferent arteriole has the opposite effect.

What is the function of afferent arteriole and efferent Arteriole?

Afferent arteriole is a branch of the renal artery that brings in blood to the glomerulus. Efferent arteriole is a branch of the renal artery that drains blood away from the glomerulus. Afferent arteriole carries blood to the glomerulus. Efferent arteriole takes blood away from the glomerulus.

How are the afferent and efferent arterioles innervated?

Bruce M. Koeppen MD, PhD, Bruce A. Stanton PhD, in Renal Physiology (Fifth Edition), 2013 The afferent and efferent arterioles are innervated by sympathetic neurons; however, sympathetic tone is minimal when the volume of extracellular fluid is normal (see Chapter 6 ).

Can a sympathetic afferent impair the function of the heart?

Sympathetic afferents relay pain sensation from the heart. The following resources will help you to master the innervation of the heart and cement your knowledge. Injury to the cardiac plexus, or in fact, to any of the contributaries to the cardiac plexus can impair the function of the heart.

How are sympathetic nerves responsible for the heart beat?

Sympathetic nerves are responsible for: the ‘fight or flight’ response, causing our heart to beat faster. Afferent fibres also form part of the cardiac plexus. They return to the central nervous system via both the sympathetic cardiac branches and the cardiac nerves from the right and left vagus nerves.

How is renin secretion affected by afferent arterioles?

Sympathetic nerve activity. Activation of the sympathetic nerve fibers that innervate the afferent arterioles increases renin secretion via β-adrenergic receptor stimulation. Renin secretion is decreased as renal sympathetic nerve activity is decreased.