QS Study

Renal blood flow means the total amount of blood which is transported through both kidneys per minute. This rate determines how much solute is retained or discarded, how much water is retained or discarded, and ultimately, the osmolarity of blood and the blood pressure of the body.

  • Normal renal blood flow (RBF): 1200 ml/min (21% of cardiac output).
  • Renal plasma flow: 650 ml/min.

In humans, the kidneys together receive roughly 25% of cardiac output, amounting to 1.1 L/min in a 70-kg adult male. RBF is closely related to renal plasma flow (RPF), which is the volume of blood plasma delivered to the kidneys per unit time.

Fig: Renal blood flow

Mechanism of Renal blood flow –

Renal artery

1st and 2nd division

Segmental artery

Interlobular artery

Arcuate artery

Afferent arteriole breaking into 30-50 divisions

Glomerular capillary

Efferent arteriole

Intralobular vein

Arcuate vein

Interlobular vein

Segmental vein

Ant. and post. branch

Renal vein