Question

What is the volume of glomerular filtrate formed in one day?
A. 170 - 180 l
B. 1000 l
C. 220 - 250 l
D. 50 ml

Answer 1

Hint: The glomerular filtration also known as GFR is the ultrafiltration of the plasma and its contents in the glomerulus. It is governed by 2 major factors 1. Filtration coefficient (kf) 2. Pressure gradient or starling force (hydrostatic and osmotic pressure gradient)

Complete answer: GFR is the rate at which plasma is filtered by the kidney glomeruli. So this filtration is affected by many factors, some of the factors we discuss here-
1. Change in blood flow of the kidney that is the alteration in renal blood flow
2. Glomerular capillary hydrostatic pressure
3. Change in capsular hydrostatic pressure
4. Osmotic pressure
5. Permeability of Glomerular capillary
6. Effective filtration surface area
7. Size, shape, and electrical charge of the macromolecules
GFR= kf * Net filtration pressure GFR is calculated by measuring any chemical that has a steady level in the blood and is freely filtered but neither reabsorbed nor secreted by the kidney. The total volume of blood that is passing through the kidneys is about 1200 ml per min or about one-fourth of the entire cardiac output. As the plasma passes through the glomerulus, due to filtration it loses more than 10% of its volume to the glomerular filtrate. The normal glomerular filtration rate amounts to about 180 liters each 24 hours. This is 4.5 times the amount of fluid present in the entire body. The renal tubules reabsorb about 99% of the filtrate into the blood, leaving only about 1.5 litres to be excreted as urine during a 24-hour period.
So, option A is correct.

Note: GFR is usually accepted as the best overall index of kidney function. A clinician or medical laboratory can estimate GFR from a person's serum creatinine level and some or all of the following variables: gender, age, weight, and race.