Renal regulation of water and acid-base balance Flashcards
What is osmotic pressure directly proportional to?
No of solute particles, not size
What is osmolarity?
Concentration x no of disassociated particles
=osm/l or mOsm/L
What is the total fluid volume ?
60% of body weight
How is the body fluid split between extracellular and intracellular
1/3 - extra cellular
How is extra cellular fluid split?
What are the two ways in which water can be lost ?
Unregulated and regulated
What are the ways water can be loss - unregulated
Sweat
Feces
Vomit
Water evaporation from respiratory lining and skin
What are the ways water be loss - regulated ?
Renal regulation – urine production
What are 2 types of renal regulation
Positive water balance and negative water balance
What is positive water balance ?
What is negative water balance?
Where is the water reabsorbed
2/3 in PCT, 15% in descending limb
What is countercurrent multiplication?
Step 1 - active salt reabsorption in thick ascending loop of Henle
Step 2 -passive water reabsorption in descending loop of Henle
What is the purpose of urea recycling*
To have urea concentration in the medulla interstitium
To get rid of urea with as little water as possible
Which side is UTA1?
Apical
Which side is UTA3?
Basolateral
What is vasa recta
Capillary network surrounding the nephron in the medullary region
What happens when urea enters the nephron via the thin descending limb?
Enters through UTA2 receptor
What is ADH and what is its main function
Protein of 9 amino acids
Promote water reabsorption from collecting duct
Other functions: helps with urea recycling an sodium reabsorption
Where is ADH produced
Hypothalamus (neutrons in supraoptic and paraventricular nuclei)
Where is ADH stored
Posterior pituitary
How is a fluctuation of plasma osmolarity detected
By osmoreceptors
What factors stimulate ADH production and release?
Increase in plasma osmolarity
Hypovolemia - decrease in blood pressure
Nausea
Angiotensin II
Nicotine
How is change in blood pressure detected and where are signals sent
By baroreceptors and sent to hypothalamus