What is the relation between GFR and afferent arteriolar resistance?
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 afferent arteriole has the opposite effect.
What causes the afferent arteriole to dilate?
Afferent arteriole constriction leads to decreased GFR and decreased RPF, resulting in no change in FF. One important function of prostaglandins is to dilate the afferent arteriole.
What happens to GFR when 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.
How does the afferent arteriole control blood pressure?
The afferent arterioles are a group of blood vessels that supply the nephrons in many excretory systems. They play an important role in the regulation of blood pressure as a part of the tubuloglomerular feedback mechanism. The afferent arterioles later diverge into the capillaries of the glomerulus.
What is the function of the afferent and efferent arterioles?
Afferent and efferent arterioles are responsible for the supply of blood to the glomerulus of the kidney. The glomerulus is a branch of blood capillaries. It functions by receiving the blood through an afferent arteriole and the blood comes out through the efferent arteriole.
What happen to blood pressure resistance and NFP when efferent arterioles constrict?
If the arterial blood pressure remains constant then contracting either vessel reduces blood flow as it increases resistance. However if you constrict the efferent arteriole you are increasing the pressure difference between the two and filtration pressure increase.
What type of response by the afferent arterioles would you expect if blood pressure decreased?
When blood pressure drops, the same smooth muscle cells relax to lower resistance, increasing blood flow. The vasodilation of the afferent arteriole acts to increase the declining filtrate formation, bringing NFP and GFR back up to normal levels.
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.
What type of response by the afferent arterioles would you expect if blood pressure increased?
Regulation of Fluid and Electrolyte Balance The myogenic response is the reflex response of the afferent arterioles to changes in blood pressure. Increased blood pressure increases the tension in the vascular wall, and the vascular smooth muscle contracts.
What is the function of the efferent arteriole?
The efferent arterioles form a convergence of the capillaries of the glomerulus, and carry blood away from the glomerulus that has already been filtered. They play an important role in maintaining the glomerular filtration rate despite fluctuations in blood pressure.
What is the main difference between afferent and efferent arterioles?
The main difference between afferent and efferent arterioles is that afferent arterioles carry blood to the glomerulus whereas efferent arterioles take the blood away from the glomerulus. An afferent arteriole is a branch of the renal vein, which carries blood containing nitrogenous wastes.
What type of response does afferent arterioles have?
The afferent arteriolar myogenic response contributes to the autoregulation of renal blood flow (RBF) and glomerular filtration rate (GFR), and plays an essential role in protecting the kidney against hypertensive injury.
