Question

Glomerular hydrostatic pressure is present in

• A. tubule of kidney
• B. Bowman’s capsule
• C. glomerulus of uriniferous tubule
• D. Malpighian tubule

Answer 1

Answer: (D)

Ultrafiltration occurs in Malpighian corpuscles due to pressures and other specialities in these corpuscles. Filtrate pressures
(a) Glomerular blood hydrostatic pressure $=+75mmHg$ due to wide diameter of afferent arteriole and narrow. diameter of efferent arteriole. It supports filtration.
(b) Blood colloid osmotic pressure $=-30mmHg$ as a result of substances dissolved in blood. It opposes filtration.
(c) Renal capsular hydrostatic pressure $=-25mmHg$ due to fluid already present in cavity of Bowman's capsule. It also opposes filtration. Effective filtration pressure $(EFP)+75mm,-30,-25mm$ $=+20mm$