How is a high blood pressure built up in a glomerulus? Why is this high blood pressure needed?
Here's my assessment.
The efferent arteriole has a smaller diameter than the afferent arteriole.
This causes a blood back-up in the glomerular capillaries.
Therefore, fluid and solute are forced out from the blood and into the glomerular capsule.
The glomerular blood hydrostatic pressure (
However, the solute concentration in the glomerular capillaries is greater than that on the other side of the glomerular membrane.
Thus there is a blood colloid osmotic pressure (
The Bowman's capsular hydrostatic pressure (
The net filtration pressure (
The glomerular filtration rate (
If that happens, many substances discharged in the urine will be resorbed.
The maintenance of sodium balance and control of body fluid volume will be severely compromised.