Question

When glomerular filtration does occurs in Bowmans capsule?

• A. When hydrostatic pressure of blood in the glomerulus is 70 mm Hg and net filtrate pressure is -25 mm Hg
• B. When hydrostatic pressure of blood in the glomerulus is 70 mm Hg and not filtrate pressure is -35 mm Hg
• C. When hydrostatic pressure of blood in the glomerulus is 70 mm Hg and net filtrate pressure is 10 mm Hg
• D. When hydrostatic pressure of blood in the glomerulus is 70 mm Hg and net filtrate pressure is -70 mm Hg

Answer 1

Answer: (C)

Ultra filtration occurs due to GHP (Glomerular hydrostatic pressure). GHP is due to narrow efferent arteriole. It is about 60-75 mm Hg. The colloid osmotic and capsular hydrostatic pressures are respectively about 32 mm Hg and 18 mm Hg, which resist ultrafiltration. Thus net effective filtration pressure is about 10 (60 - 32 + 18) mm Hg.