Renal blood flow

As renal blood flow (RBF; Engl. Renal blood flow ) is the amount of blood indicated that per minute through the kidney flows as renal plasma flow (RPF), the amount of the kidneys per minute flowing through the blood plasma .

The renal blood flow is about one fifth of the cardiac output , about 1.2 liters per minute. Depending on the functional state of the kidneys, the value can vary greatly (according to Peters, the renal plasma flow is about 600 ml / min and the renal blood flow is about 1100 ml / min). 90% of the blood flows through the renal cortex , 9% through the medulla and 1% through the renal papilla. Although the kidneys make up only a small proportion of the body's weight, they receive a significant part of the bloodstream and are therefore one of the organs with the most blood supply. Based on weight, the kidneys have better blood flow than the heart, brain and liver. The RBF remains well regulated by the Bayliss effect even with major fluctuations in the systemic arterial blood pressure.

The renal blood flow is determined by the pressure difference ΔP between the renal artery and vein and the renal vascular resistance R:

{\ displaystyle RBF = {\ frac {\ Delta P} {R}}}

If the hematocrit (proportion of erythrocytes in the volume of blood) and renal plasma flow are known, the following applies:

{\ displaystyle RBF = {\ frac {\ text {RPF}} {1 - {\ text {Hematocrit}}}}}

literature

Hamid Abdolvahab-Emminger (Hrsg.): Physikum exact: the entire examination knowledge for the 1. ÄP. Thieme, 2005. ISBN 3-13-107034-X . P. 562
Michael Gekle (Hrsg.): Pocket textbook Physiology. Thieme, Stuttgart 2010. ISBN 978-3-13-144981-8 . P. 349 ff.
Christian Hick, Astrid Hick: Short textbook Physiology. Urban & Fischer, 2013. ISBN 978-3-437-41895-2 . P. 220.

Individual evidence

↑ J. Peters: Effects of ventilation on kidney and liver function. In: J. Kilian, H. Benzer, FW Ahnefeld (ed.): Basic principles of ventilation. Springer, Berlin a. a. 1991, ISBN 3-540-53078-9 , 2nd, unchanged edition, ibid 1994, ISBN 3-540-57904-4 , pp. 364-378; here: p. 365.
↑ Gekle 2010, p. 349
↑ Hick 2013, p. 220

[1] J. Peters: Effects of ventilation on kidney and liver function. In: J. Kilian, H. Benzer, FW Ahnefeld (ed.): Basic principles of ventilation. Springer, Berlin a. a. 1991, ISBN 3-540-53078-9 , 2nd, unchanged edition, ibid 1994, ISBN 3-540-57904-4 , pp. 364-378; here: p. 365.

[2] Gekle 2010, p. 349

[3] Hick 2013, p. 220