Renal Blood Flow
Start with the big picture
The kidneys receive a substantial share of cardiac output, and renal blood flow is closely linked to renal plasma flow and the filtration fraction. Blood passes through glomerular capillaries, which support filtration, and then through peritubular capillaries or the vasa recta, which support reabsorption and secretion. Autoregulation helps keep renal blood flow and GFR relatively constant across a range of arterial pressures, using the myogenic mechanism and tubuloglomerular feedback. The juxtaglomerular apparatus helps coordinate sensing and vascular responses. Sympathetic activity and hormonal factors also influence perfusion: angiotensin II preferentially constricts the efferent arteriole, while prostaglandins can counter vasoconstriction.
What you'll learn
- Describe the scale of renal blood flow and its relationship to cardiac output.
- Trace the roles of the glomerular and peritubular capillary beds.
- Explain how the myogenic mechanism and tubuloglomerular feedback contribute to autoregulation.
- Summarize how the juxtaglomerular apparatus integrates sensing and renal vascular responses.
- Identify neural and hormonal influences on renal perfusion.
Continue your study
Work through the complete notes and reinforce the topic with the study tools available in the full lesson.
