free water clearance


Also found in: Dictionary, Thesaurus, Legal, Financial, Encyclopedia, Wikipedia.

free wa·ter clear·ance

the amount of water excreted in the urine beyond that which would accompany the excreted solutes if the urine were isosmotic with plasma; it represents the loss of body water in excess of solute tending to raise body osmolality and making urine hyposmotic. Unlike other clearances, it is calculated by subtracting the osmolal clearance from the actual volume of urine excreted per minute. A negative value for free water clearance represents the amount of water that the body has reclaimed from isosmotic tubule fluid to make the urine hyperosmotic and to lower body osmolality.

free

not tied; unconfined.

free bullet humane killer
see humane killer.
free electricity
the presence of uncontrolled electrical current in solid materials at low amperages and voltages, usually due to faulty wiring and poor earthing (grounding) of the electrical power system. It causes restlessness, and failure of letdown of milk. In some cases when the circumstances are suitable there may be stunning of animals and rarely fatal electrocution.
free fatty acids
most fatty acids in the body are combined with alcohols in the form of triglycerides. Free fatty acids are produced during digestion and metabolism but most of them in the circulation are combined with protein during this phase.
free fluid
fluid in the body, other than in the alimentary or urinary tracts, which is not part of tissue fluid but free in a body cavity or as a discrete mass in an organ.
free gas bloat
see ruminal tympany.
free hormone hypothesis
the unbound fraction of hormone is the indicator of what is available to tissues, available for metabolism and excretion. See also free thyroxine.
free return
a return of service for a mare to the same stallion in the next season if she does not produce a live foal.
free stall housing
cow accommodation in which there are enough stalls for each cow to have one but the cows are not tied in; they are free to lie down in a cubicle or to feed or to seek other cows coming on heat.
free T4 index
see free thyroxine.
free water clearance
the capacity to excrete urine of lower osmolality than plasma, thus avoiding depletion of salt reserves.