Sage-Tips

What happens to glomerular filtration rate when the afferent arteriole dilates?

Increased blood volume and increased blood pressure will increase GFR. Constriction in the afferent arterioles going into the glomerulus and dilation of the efferent arterioles coming out of the glomerulus will decrease GFR. Hydrostatic pressure in the Bowman’s capsule will work to decrease GFR.

What happens when there is decreased blood volume to the Renals?

Narrowing of the arteries prevents normal amounts of oxygen-rich blood from reaching your kidneys. Your kidneys need adequate blood flow to help filter waste products and remove excess fluids. Reduced blood flow to your kidneys may injure kidney tissue and increase blood pressure throughout your body.

What is the role of afferent and efferent arteriole on glomerular filtration?

Afferent arteriole gives only oxygenatedblood which is loaded with waste marterials. But efferent arteriolr send deoxygenated blood to renal vien .

What happens when afferent Arteriole constricts?

Constriction of the afferent arterioles has two effects: it increases the vascular resistance which reduces renal blood flow (RBF), and it decreases the pressure downstream from the constriction, which reduces the GFR. Dilation of the afferent arterioles has the opposite effects.

Why does angiotensin constrict efferent Arteriole?

To do this, angiotensin II constricts efferent arterioles, which forces blood to build up in the glomerulus, increasing glomerular pressure. The glomerular filtration rate (GFR) is thus maintained, and blood filtration can continue despite lowered overall kidney blood flow.

What causes efferent Arteriole constriction?

1. The afferent and efferent arterioles constrict in response to α-adrenergic stimulation. This vasoconstriction predominantly affects the afferent arteriole, effectively reducing hydrostatic pressure within the glomerular capillary lumen and decreasing glomerular filtration.

When the afferent arterioles of glomerular capillaries constrict?

Constriction of the afferent arterioles has two effects: it increases the vascular resistance which reduces renal blood flow (RBF), and it decreases the pressure downstream from the constriction, which reduces the GFR.

What happens when the efferent arteriole constricts?

During efferent arteriole constriction, GFR is increased, but RPF is decreased, resulting in increased filtration fraction. During a state of increased plasma protein concentration such as during multiple myeloma, GFR is decreased with no change in RPF, resulting in decreased FF.

Why does RPF decrease with efferent constriction?

During efferent arteriole constriction, GFR is increased, but RPF is decreased, resulting in increased filtration fraction. It reduces the formation of angiotensin II, which in turn decreases GFR by preventing the constriction of efferent arterioles.

How does vasoconstriction of the afferent arteriole affect blood flow?

This vasoconstriction of the afferent arteriole acts to reduce excess filtrate formation, maintaining normal NFP and GFR. Reducing the glomerular pressure also functions to protect the fragile capillaries of the glomerulus. When blood pressure drops, the same smooth muscle cells relax to lower resistance, increasing blood flow.

What happens when arterioles are dilated and constricted?

The constriction of arterioles increases resistance, which causes a decrease in blood flow to downstream capillaries and a larger decrease in blood pressure. Dilation of arterioles causes a decrease in resistance, increasing blood flow to downstream capillaries, and a smaller decrease in blood pressure.

What is the difference between the afferent and efferent arteriole?

The afferent arteriole has a larger diameter in the cortical nephron. The efferent arteriole has a smaller diameter in the cortical nephron. Afferent arteriole maintains the blood pressure. Efferent arteriole maintains the glomerular filtration rate.

What is the difference between vasoconstriction and vasodilation?

Specifically in arteries, vasoconstriction decreases blood flow as the smooth muscle in the walls of the tunica media contracts, making the lumen narrower and increasing blood pressure. Similarly, vasodilation increases blood flow as the smooth muscle relaxes, allowing the lumen to widen and blood pressure to drop.