PHYS20008 Lecture Notes - Lecture 23: Inulin, Aldosterone, Afferent Arterioles
25 May 2019
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Document Summary
The characteristics needed in order to measure gfr are: It is exogenous (from outside the body) It is not metabolised (not broken down anywhere before the kidney) If we know volume of insulin and volume of urine, we can calculate gfr. Clearance is the rate of urinary excretion of a substance relative to its plasma concentration. It tells us how good our kidneys are at clearing a particular substance out of our plasma. Where u is the units of the substance. Even if map increases in the gfr will not change due to homeostasis. Normal blood pressure is between 80 mm hg and 180 mm hg homeostasis only maintains gfr between these. They then constrict to maintain the gfr. Attached to the afferent arteriole is a structure called the macula densa which sits right next to the ascending loop of henle. The macula densa samples the fluid in the loop to see if it is correct.
