PHY3171 Lecture Notes - Lecture 9: Central Venous Pressure, Renal Function, Renal Artery
Document Summary
L8: role of the kidneys in the long-term regulation of bp. Arterial pressure influences kidney function via pressure natriuresis/diuresis. Additionally, kidney function also influences arterial pressure via influencing: blood volume cardiac filling cardiac output. If bp goes up by 10 mmhg, will always bring it down by 10 mmhg. Central and peripheral blood volume: blood transfusion, plasma transfusion, saline infusion. Central blood volume: head-out water immersion, feet-up tilt, lower body positive pressure. Ecf blood volume central venous pressure cardiac output. Therefore, increases in extracellular fluid, increases cardiac output. Occurs even though renal blood flow and glomerular filtration rate are well autoregulated. Therefore, mainly due to reduced tubular reabsorption of sodium and water. As you increase arterial pressure, renal tubules absorb less salt + water make more urine. Neural + hormonal factors modulate pressure diuresis/natriuresis: sympathetic nerves, angiotensin ii, atrial natriuretic peptide. Most experiment look at changing arterial pressure and then the effect on salt + water excretion.