Renal circulation and cortex
summarised as:
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Myogenic mechanism
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Tubuloglomerular feedback
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Sensor: macula densa - sits between thick ascending loop and DCT, part of juxtoglomerular apparatus
- Chemoreceptors
- Stimulus: NaCl concentration
- Action: ↓ NaCl concentration (indicating low flow) → afferent arteriole dilatation; ↑ renin release → systemic vasoconstriction
hormonal control of renal autoregulation
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Vasoconstrictors = ↓ renal blood flow:
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Vasodilators = ↑ renal blood flow:
- ANP, BNP
- Prostacyclin
- Bradykinin
renal sympathetic stimulation decreases GFR
- minor effect only with strong stimulation
- seems to be somewhat autoregulatory effect
where the nephron sits
- blood supply to medulla from vasa recta
- Medullary blood flow is approximately 20-100 ml/min/100g in a healthy adult.
- Cortex blood flow is approximately 500 ml/min/100g in a healthy adult.