Download Chapter 20 powerpoint – Kidney and Nephron

Location
Kidney Structure
Kidney Function
 Regulate volume, composition, and pH of
body fluids
 Remove metabolic wastes from blood and
excrete (mainly N and S compounds from
protein metabolism)
 Control rate of rbc formation erythropoietin
 Regulate blood pressure - renin
 Absorbs Ca2+ and activates vitamin D
Dialysis
Peritoneal Dialysis
Hemodialysis
Blood Supply
Renal Artery & Vein =
contain 15-30% of total cardiac output
aka –
Bowman’s
Capsule
aka -Loop
of Henle
Nephron
Glomerulus
Glomerulus
Juxtaglomerular
Apparatus
Renin secretion –
regulates [Na+ ]
and therefore,
blood volume
Collecting Duct =
simple cuboidal epithelium
Tubules
D=distal P=proximal
Urine Formation
180 L of fluids are
filtered every
24 hours!
Urine Formation Overview
Blood
pressure
causes
filtration
by size of
molecule
Blood Filtration
Water
Electrolytes
Glucose
Urea
Urine Composition
Urea
Uric Acid
 By- product of aa catabolism
 Reflects amt. of protein in
diet
 Contributes to water
reabsorption
 By- product of nucleic acid
catabolism (A & G)
 Filtered out in glomerulus
 Cause of Gout
90% is Water
Creatinine
• Volume varies with fluid intake and
environment
• Waste product of muscle action
Trace amounts of:
• Amino acids, electrolyes, glucose
Gout
Gout
Urinary Excretion in Nephron
ADH – antidiuretic
hormone
Regulates water volume - Makes DCT
permeable to water for reabsorption
Secreted when dehydrated =
more concentrated urine
Alcohol
Decreases ADH, which
decreases water
reabsorption
Decreases Na+ absorption,
which decreases amount of
water you will hold.
Caffeine
Kidney Stones