fluid
refers to water
electrolytes
- definition
- function
inorganic compounds that dissociate in water to form ions
-can conduct an electrical current in solution
sodium
most abundant ion of the ECF and main contributor to the osmolarity
osmolarity
- definition
- osmolarity of body fluids
solute concentration of blood
-300 mOsm/L
3 hormones that play a key role in regulating fluid and electrolyte balance
- ADH (released from posterior pituitary)
- aldosterone (adrenal cortex)
- atrial naturetic peptide (heart)
antidiuretic hormone
- function
- where is it released from
- stimulus
- how is blood osmolarity detected
- prevents fluid loss and promotes the conservation of body water
- posterior pituitary
- increase in blood osmolarity (increased solute concentration and decrease in water concentration)
- by osmoreceptors
how does ADH to increase in blood osmolarity
-results
- by increasing the reabsoption of water (water is conserved) and stimulates thirst
- small vol of concentrated urine
aldosterone
- 2 functions
- results
- regulates blood Na+ levels (specifically increase sodium reabsorption in the DCT and CD - conserves sodium)
- increases secretion of potassium
- regulates blood Na+ levels (specifically increase sodium reabsorption in the DCT and CD - conserves sodium)
- decrease in blood and increase in urine
aldosterone
- released from
- stimulus
- adrenal cortex
- decrease in sodium or increase in potassium; activation of the renin-angiotensin system
renin angiotensin system
- type of cells
- release what
- stimulus
- juxtaglomerular cells
- renin
- decrease in blood vol.
- a reduction in bp
- stimulation by the simpathetic system
- decrease in blood vol.
renin
-function
-enzyme that converts angiotensinogen to angiotensin I and then angiotensin I is converted to angiotensin II by angiotensin converting enzyme
angiotensin II
-2 functions
- stimulates aldosterone release from adrenal cortex
2. causes vasoconstriction (increases bp)
atrial natiretic peptide
- definition
- released from
- 3 functions
- promotes both fluid and sodium loss by the kidneys
- atria
- decreases aldosterone release, resulting in a decrease in sodium reabsorption and increased sodium loss in urine
- decreases ADH release which decreases water reabsorption and increases water loss to lower blood vol and pressure
- decreases thirst
- decreases aldosterone release, resulting in a decrease in sodium reabsorption and increased sodium loss in urine
Group: 25 ml of water
- blood vol
- blood osmolarity
- urine vol
- urine specific gravity
- urine chloride
- no change
- no change
- decrease
- decrease
- no change
Group: isotonic (1000 ml 0.9% NaCl)
- blood vol
- blood osmolarity
- urine vol
- urine specific gravity
- urine chloride
- increase
- no change
- decrease
- decrease
- increase
Group: water loaded (1000 ml water)
- blood vol
- blood osmolarity
- urine vol
- urine specific gravity
- urine chloride
- increase
- decrease
- increase
- decrease
- decrease
Group: salt loaded (150-250 ml 2% NaCl)
- blood vol
- blood osmolarity
- urine vol
- urine specific gravity
- urine chloride
- increase a little
- increase
- decrease
- increase
- increase
which group produced the greatest urine vol during the 90 min period and why?
water loaded group because they drank alot of water adnd ADH decreased
which group produced urine with the lowest specific gravity and chloride content?
the water loaded because of the extra water. it wasnt reabsorbed
explain the diff in color between the urine of the four groups
more salt concentration in urine = dark yellow
which group produced a small vol of concentrated urine? why?
salt loaded because blood osmolarity; ADH increases
how did the specific gravity of the urine produced by the salt loaded group compare with that of the isotonic group?
the salt loaded group held on to the water where as the isotinic group did not
how did the vol of urine output compare to the vol drank in each group
water loaded group had the highest vol
what hormone was inhibited in the salt loaded group?
-what hormone was stimulated
- aldosterone
- ADH
