Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key


Play button


Play button




Click to flip

27 Cards in this Set

  • Front
  • Back
Name three functions of the kidney
1.electrolyte balance
2.acid-base balance
3.regulation of normal fluid volume and osmolarity
4.excretion of wastes
5.long-term control of BP
6.synthesis and release of renin
How is molarity defined? How is molality defined?
*Moles solute/liter of solution
*Moles solute/kilogram of solution
What are the normal concentrations of NaCl, KCl, and glucose?
*NaCl = 140mM (140meQ/L)
*KCl = 3.5-5.0meQ/L
*glc = 5mM (80-100mg/dL)
What is the formula for osmolarity? How is osmolarity related to the concentration of water?
*Osm = molar concentration x number of dissociable particles
*osmolarity represents the inverse of water concentration
What is the normal value for the colloid osmotic pressure of plasma?
How is total body water calculated? What is a normal value for a 70-kg man? How is total body water divided between the extracellular and intracellular compartments?
*weight (kg) x fraction of water
*42 L
*2/3 in the intracellar compartment (28L), 1/3 in the extracellular compartment (14L)
How is the extracellular fluid compartment divided between the plasma and interstitial fluid?
*3/4 as interstitial fluid (10.5L)
*1/4 as plasma (3.5L)
What is the normal osmolarity of ECF and ICF? Which is at greater risk for change and why?
*ECF, because it is subject to external influences
There are 2 ways that isosmolar can be defined - what are they?
*two solutions having the same osmolarity
*a solution that has the same osmolarity as plasma
How does a hyposmolar solution affect cells? What about a hyperosmotic solution?
*In a hyposmotic solution, water will run into cells and cause them to swell and lyse
*In a hyperosmotic solution, water will flow out of the cell causing it to shrink
How does water loading affect the osmolarity and volume of ECF and ICF?
It will cause a decrease in the osmolarity and an increase in the volume of ICF and ECF.
How does salt loading affect osmolarity and volume of ICF and ECF?
*increases the osmolarity of ECF and ICF
*decreases the volume of ICF
*increases the volume of the ECF
How does an infusion of isosmolar solution affect the volume of the ECF and ICF?
This causes an increase in the volume of the ECF only.
In terms of the steady state, what is meant by positive balance? Negative balance?
*positive balance means that intake exceeds output
*negative balance means that output exceeds intake
How many juxto-medullary nephrons are there relative to the number of cortical nephrons?
There are around nine times as many cortical nephrons as there are juxto-medullary ones.
What is meant by ultrafiltration?
Fluid is moved from the glomerular capillaries to Bowman's space.
What is meant by reabsorption?
Fluid is moved from the tubule lumen into the plasma.
What is meant by secretion? Excretion?
*Fluid is moved from the plasma to the tubule lumen
*fluid is moved from the tubule lumen out of the body
Describe (in general terms) the action of the PCT - is it reabsorptive or secretory? What solutes are affected and how?
The PCT resorbs 2/3 of all filtered water and NaCl, all filtered glucose, and secretes drug metabolites.
The descending LOH reabsorbs water and NaCl.
False: the descending LOH reabsorbs water but secretes NaCl.
What is the action of the ascending LOH on water?
It is impermeable to water and thus has no effect. It does reabsorb NaCl though.
How are the DCT and collecting ducts affected by ADH and aldosterone?
*they reabsorb water under the influence of ADH
*they reabsorb Na+ and secrete K+ under the influence of aldosterone
Renal blood supply consumes roughly what percentage of cardiac output?
How is renal blood flow divided between the cortex and medulla?
The cortex receives ~90% while the medulla receives only ~10%.
What is the pressure in the glomerular capillaries? How does this compare to pressure in systemic capillary beds? What is the advantage of this?
*much higher (systemic is 15-20mmHg)
*drives filtration
What is the pressure in the peritubular capillaries? Of what advantage is this?
It is normal (close to 15-20mmHg). This favors reabsorption.
Does osmolarity take into account all particles in a solution?
No - it pertains only to those that do not freely cross the membrane.