First, perspiration is that fluid which is lost through
the skin. Normally, a person is unaware of
perspiration unless the temperature is extremely
hot or strenuous exercise has just taken place.
Perspiration contains approximately 45 mEq of
sodium, 4.5 mEq of potassium, and 57.5 mEq of
chloride in each liter.
NOTE: Most people have difficulty grasping the
significance of the volume of perspiration lost
during a 24-hour period of time. In order to
illustrate this point, the next question will ask you
to estimate the volume of fluid lost during a 24-
hour period of time in the form of perspiration. Do
not attempt to find this figure in the above
paragraph. Sufficient data has not been provided
for an accurate estimate. Do not be surprised if
your estimate is off by 25 or 50 milliliters.
QUESTION: About ______ ml of fluid lost in the
form of perspiration over a 24-hour period of time.
Solution to Frame 36
A small volume of fluid is lost every day in the
ANSWER: Approximately 650
feces. Usually only 100 milliliters of fluid is lost in
milliliters of perspiration is lost
normal stools. This demonstrates the efficiency of
during a normal day by a normal
the large intestine in absorbing the water passing
through it. A third means of fluid loss is by
respiration. Respiration occurs around-the-clock;
however, most people are unaware that they are
exhaling fluid (water vapor) every time they
breathe. This fluid loss through the lungs only
becomes apparent during cold weather. During
cold weather, the water vapor can be seen when it
is exposed to low temperatures.