RENAL PHYSIOLOGY 3 Flashcards
fluid volume regulation is almost mediated by changes in ECF osmolarity
_________ is almost entirely mediated by changes in water balance
osmoregulation
when fluid intake is greater than fluid output there is _________
overhydration
when fluid intake is lesser than fluid output there is ________
dehydration
if intake exceeds water loss there is ________
positive water balance
if intake is less than water loss there is _________
negative water balance
inside the cell the major cation is _______
potassium
outside the cell the major cation is _______
sodium
there are three measurements of concentration
T,O,O
tonicity
osmolarity
osmolality
in ______ solution, cells do not swell or shrink
a cell is placed in a solution of impermeant solutes having an osmolarity of 282 mOsm/L
isotonic solution
in ________ solution there is lower concentration of impermeant solutes (<282 mOsm/L)
water will diffuse into the the cell causing it to swell, will continue to diffuse into the cell
hypotonic solution
in _____ solution there is a higher concentration of impermeant solutes
the cell will shrink until the two concentrations become equal
hypertonic solution
infuse isotonic fluid
ECF volume ______
ECF osmolarity ______
ICF volume and osmolarity will _________
increases
will not change
will not change
infuse hypotonic fluid
ECF volume ______
ECF osmolarity ______
ICF volume _________
ICF osmolarity _______
increase
increase
decrease
decrease
infuse hypertonic fluid
ECF volume ______
ECF osmolarity ______
ICF volume _________
ICF osmolarity _______
increase
decrease
increase
increase
also called vasopressin
action: increase the permeability of the distal tubules and collecting ducts to water
antidiuretic hormone
3 major effects of ADH on the Kidneys
1._______ the permeability of the distal tubules and collecting ducts to water
2. _______ the permeability of the inner medullary portion of the collecting duct to urea
3. _________ the reabsorption of the NaCl by the thick ascending limb of Henle’s loop, distal tubule, and collecting ducts
increases
increases
stimulates
produces hyperosmolar medullary interstitium
ascending loop of henle
impermeable to water
Na+ Cl+ K+ co-transporter
countercurrent multiplier
preserves hyperosmolarity of the medullary interstitium
minimizes washout of solutes from the medullary interstitium
medullary flow is low (1-5% of the total renal blood flow)
medullary blood flow is slow which minimizes solute loss
countercurrent exchanger
calculates the amount of free water generated by the kidneys when dilute or concentrated urine is formed
derived from concept of clearance
free water clearance
clearance of the total solutes from plasma by the kidneys
osmolar clearance
expressed as osmolar clearance
volume of plasma cleared of solutes per minute
total clearance of solutes
calculated as the difference between water excretion (urine flow rate) and osmolar clearance
free water clearance
excess water is excreted by the kidney
urine osmolarity is lesser than plasma osmolarity
water excretion
positive free water clearance
excess solutes are removed from the body
urine osmolarity is greater than plasma osmolarity
water conservation
negative free water clearance
