Question

Dilating the afferent arteriole and constructing the efferent arteriole to the renal corpuscle will cause which pressure to rise?

A. Glomerular hydrostatic pressure

B. Glomerular osmotic pressure

C. Capsular hydrostatic pressure

D. Capsular osmotic pressure

Answer 1

A. correct answer

By dilating afferent arteriole the blood flow to the glomerulus will increase. By constricting efferent arteriole (which takes blood away from the glomerulus), excess blood stays in the glomerulus which exerts more pressure in the glomerulus increasing the glomerular hydrostatic pressure.

B. wrong option

osmotic pressure only depends on the percentage of osmotically active substances in the blood. it is not affected by the diameter change of blood vessels.

C. wrong option

capsular hydrostatic pressure might slightly increase because of the increased filtration secondary to an increase in glomerular hydrostatic pressure.

D. wrong option

capsular osmotic pressure is normally negligible and it is dependent on the presence of the osmotically active substance in the Bowmans capsule. it is independent of the diameter of these blood vessels.