Fluid Balance

What is the treatment for ascities?

sodium restrictionalbumin infusion (keeps the water inside of the cells instead of in the peritoneal space)diuretics such as Spironolactone (Aldactone) to block aldosterone in distal tubal

What are the 3 major places that your total body water is distributed?

Intracellular fluid (65%)Interstitial fluid (25%)Plasma (8%)

A heart failure patient will have a ______ fluid balance

Positive (input > output)

Define filtration

Net fluid movement into or out of the capillaryIs determined by the difference between the forces favoring filtration and those opposing it (tug of war)

Interstitial hydrostatic pressure

Pushes water into the capillary

Interstitial oncotic pressure

Pulls water out of the capillary (this is very low pressure- little movement of water)

Capillary hydrostatic pressure

Pushing water out of the capillary

Capillary oncotic pressure

Pulling water into the capillary


Movement of water across cell membranes from less concentrated to more concentrated


The concentration of solute in a fluid (mostly sodium) per kg of water OR per L of solution (more clinically interpretable)


Movement of molecules from higher concentration to lower concentration.


Fluid and solutes move together across a membrane from an area of higher pressure to one of lower pressure

Active Transport

Substance moves across cell membranes from less concentrated solution to more concentrated; requires a carrier, and energy

What is the normal serum osmolarity?

275 to 295 milliosmoles/liter (mOsm/L)

What is the function of ADH?

�Stimulates water conservation and the thirst center

What is the function of aldosterone?

Controls Na+ absorption and K+ loss along the descending convoluted tubules and collecting duct

What is the function of the natriuretic peptides (ANP/BNP)?

Reduce thirst and block the release of ADH and aldosterone

Where are barorecptors and osmoreceptors found?

Baroreceptors: in the aorta and carotidsOsmoreceptors: in the head and kidney inside the nephron

What are the major functions of the kidney?

�Fluid balanceSolute concentration and dilutionAcid-base balanceWaste excretion

Describe autoregulation in terms of the kidney

The kidney controls the amount of blood that goes in and out of the organ; if the kidney detects a need for more blood it dilates its vessels, vasoconstricts if has too much blood inside of the kidney

What is the major measure of kidney function?

Glomerular filtration rate (GFR); based on creatine clearance. If the creatinine is high, then it means that the kidney is not functioning correctly

What does the Blood urea nitrogen (BUN) test for?

Tests for hydration status. The higher the BUN,the more dehydrated the function

What two tests together can diagnose kidney disease?


GFR increases as arterial pressure _________

Increases *Hypertension if prolonged can cause kidney failure (esp. in African Americans)

What is a normal amount of daily urine output?

1-2 L

What does urine contain?


What is the normal pH of urine?

4.6-8.0 (slightly acidic)

What is the function of the juxta-glomerular apparatus (JGA)?

Releases renin