Focus 10 Flashcards
Amino acid metabolism
Urea
Nucleic acid metabolism
Uric acid
Muscle metabolism
Creatinine
Hemoglobin metabolism
Bilirubin
Endocrine functions of urinary system
- erythropoietin
- renin
- vitamin D
Angiotensin II producer
Renin
Fluids, ions, nutrients, and waste are all filtered from blood and enter the nephron
Glomular filtration GF
Useful substances reabsorbed into blood. (Lipid soluble wastes may be reabsorbed)
Tubular reabsorption TR
Waste/excess maybe secreted from blood to nephron
Tubular secretion TS
% of the plasma that enters the glomerulus is filtered
20%
What drives filtration?
Blood pressure
What three pressures affect filtration
– Blood osmatic pressure
– Capsule hydrostatic pressure
– Globular capsule blood pressure
Is smaller than afferent arterial. Causes back up
Efferent arteriole
What is the goal of autoregulation?
Maintain constant glomular filtration rate GFR
Arterioles constrict. BP
Increased blood pressure
Arterioles dilate. BP
Decreased blood pressure
Specialized nephron region that lies close to afferent arterial and distal tubule
Juxtaglomerular apparatus JGA
Sense tubule volume/osmolarity
JGA chemoreceptors
Adjusts afferent arteriole according to changes in filtrate osmolarity or volume. Maintains GFR
Tubuloglomerular feedback
Encourages filtration
Pressure in capillaries
Opposes filtration
Other pressures
Substances reabsorbed during TR
H2O, glucose, Na, K, HCO3
Reabsorption in the proximal tubule is driven by
Na gradient set up by Na/K pump
3 Na out 2 K in
Sodium potassium pump
