Biology Forums - Study Force

I'm stuck on these questions and would greatly appreciate any and all help. Thanks.

1.         Your patient drinks 1000 ml of water.  Absorption of this volume has two effects.  It
increases the ECF volume and decreases the ECF osmolality (osmolarity).  Assume your patient had a
total body volume of 42L, an ECF volume of 14L and a plasma volume of
3L prior to comsumption of water.  Further assume an initial average osmolality of 300 mOsm.

Calculate the change in fluid osmolality of plasma if the 1000 ml remains within the vascular
space.  Calculate the new osmolality as a percent of the initial  plasma osmolality. (Assume the
water is absorbed and distributed prior to any renal excretion.)

Calculate the change in fluid osmolality of ECF if the 1000 ml is distributed throughout the
extracellular volume (plasma and interstitial fluid). Calculate the new osmolality as a percent of
the initial  plasma osmolality. (Assume the water is absorbed and distributed prior to any renal
excretion.)

Calculate the change in fluid osmolality if the 1000 ml is distributed throughout the total body
volume. Calculate the new osmolality as a percent of the initial  plasma osmolality. (Assume the
water is absorbed and distributed prior to any renal excretion.)

2.         A lost hiker is found wandering in Joshua Tree National Park.  He reports that he was
lost for two days; he spent most of his time sitting in the shade.  He had only two liters of water
when he departed his campsite 48 hours previous to being found.  He lost about 4 liters of water
per day due to evaporative water loss (respiration and sweat) but drank
only two liters of water.  Calculate the water loss and its effect on average osmolality of body
fluids.  (Assume your patient has a total body volume of 42L, an ECF volume of
14L and a plasma volume of 3L.  Further assume average osmolality of 300 mOsm; the loss of water
was distributed among all fluid compartments.)
loss of water was distributed among all fluid compartments.)

Always identify the variables you are given

I worked it out on my own.  Thanks anyway.