renal physiology 3 Flashcards
Where and what kind of reabsoption occurs throughout the nephron
PCT - bulk H2O and Na+ RB 67%, para and trans
Nephron loop - para + trans (para specific to substance)
decending - Bulk H2O 25%
accening - Bulk Na+ 25%
trans only
DCT - regulated Na+ 5%, aldostrone regulated
trans only
Collecting duct - regulated Na+ 2-3% aldostrone
regulated H2O 2-8% ADH
What is the driving force for bulk reabsorption throught the PCT and the nephron loop
PCT:
Na/K+ ATPase - Na+ into peritubular fluid
Na/glucose co transport - Na+ intracellular
Drives CL- via paracellular - balance charges
Drives H2O - balance osmolarity
Nephron loop:
decending loop - H2O
Accending loop - Na+
creates a hyper osmotic gradient
How does the body regulate when there is a change to osmolarity (non isoomotic fluid adlteration)
Osmotic change detected by osmorecptors -> sent to hypothallomus -> sent to post pituitary -> regulate ADH release
Hyperosmotic - increase ADH -> more H2O RA
Hypoosmotic - decreased ADH -> less H2O RA
What is the effect of ADH and aldostone release
Aldostone - Increased Na+ channels in apical membrane of the DCT and CD
ADH - increased aquaporins in the apical membrane of the CD- hyper osmotic gradient increases deeper into CD -> increased H2O driving force deeper into medulla
How does the body regulate when there is an increase of volume (isomotic fluid)
Increase in volume: BP increase detected in atrea of heart -> Released ANP
- reduce Na+ and H2O reabsoption -> decrease volume
Decrease in volume: Kidneys detect change -> trigger RAAS -> Aldostone + ADH release
- increase Na+ and H2P RA -> increase volume
What is the normally observed characteristics of urine
Content: urea, K H HCO3 Na, water (95-98%), creatinine, medicine, toxins
Taste: detect pH, 4.6-8 increasde with veg
Smell: non-distinct
Sight: white/ amber
What is the pathologically observed characterisics of urine
Content: RBC WBC glucose large proteins, ketone
Taste:
Smell:
Sight:
