Body Fluids Flashcards
What makes the majority of the body’s composition?
Water, which makes up 45% to 75% of the body.
What is the “Milieu Interieur”?
The “Milieu Interieur” refers to the internal
environment of the body, which includes various
body fluids.
What is the fundamental principle that directs
functional activities in the body?
The fundamental principle is maintaining
homeostasis, which is the relative constancy of the
internal environment.
What are the aspects of body fluids? (4)
The aspects of body fluids include :
volume,
distribution,
characteristics,
functions
What is the medium in which solutes are dissolved
and metabolic reactions take place?
Body water
What are body water functions? (8)
-Regulates body temperature
-Lubricates joints
-Lessens the burden on the kidneys and liver by flushing out waste products
-Carries nutrients and oxygen to cells
-Helps dissolve minerals and other nutrients to make them accessible to the body
-Helps prevent constipation
-Protects the body organs and tissues
-Moistens tissues such as those in the mouth, eyes and nose
What accounts for the large variation in water
content in different individuals?
The percentage of water in various tissues, such as
skin, muscle, heart, liver, brain, kidney, bone, and
adipose tissue. The difference in adipose tissue leads to the difference of body water.
What is the percentage of water in skin, muscle,
heart, liver, brain, kidney, bone, and adipose
tissue?
Skin: 70%, Muscle: 75%, Heart/Liver/Brain/Kidney:
70-80%, Bone: 25%, Adipose tissue: 10%.
True of False: If body water content is computed as a fraction of lean body mass (excluding fat), the differences between individuals becomes significant.
False
If body water content is computed as a fraction of lean body mass (excluding fat), the differences between individuals becomes insignificant.
How do variations in body water with age and sex
differ?
Infants have the highest percentage of body water regardless of sex.
By puberty, the oestrogen creates a fat deposit for women, reducing their body water.
As we age, body water continues to reduce because the lean body mass is reducing.
What are the standard values for a physiological
reference individual in terms of body water
percentage?
60%
How do you calculate the absolute amount of water in a 70-kg male with a body water percentage of 60%?
70 x 60% = 42 kg = ~42L.
What must be adjusted for when calculating body
water percentage in individuals? (3)
Age, sex, and weight.
What is the final concentration of a 100 mg
medication administered to a 70-kg male with 42L
of water?
(dosing : 10mg/7kg)
100 mg/42,000 mL
(0.0024mg/mL)
What is the importance of knowing the amount of
body water when administering water-soluble
medication?
It helps in determining the appropriate dose of
medication based on the concentration in the body
How does the percentage of body water affect the
final concentration of medication in the body?
A lower percentage of body water results in a higher
final concentration of medication in the body.
What is the final concentration in the body when
administering 100 mg medication to a 70-kg female
with 35 L of water in their body?
(Dosing: 10mg/7kg)
100/35 000 = 0.0029mg/mL
What is the mechanism of water intake in the body? (3)
Fluid
Food
Oxidative water from metabolism
What is the mechanism of water output in the body?
kidneys
stool
lungs
skin.
What is the dynamic steady state of body water?
Body water remains constant in health, both
internally between different compartments and
externally with the environment.
What are the obligatory losses of water per day?
Obligatory losses of water per day are (~1.5 L), which
includes insensible losses from lungs and skin, and
sensible losses from urine and stool.
What are the facultative losses of water per day?
Urine
What is the major homeostatic organ for water
balance?
The kidney is the major homeostatic organ for water
balance.
What is the difference between obligatory and
facultative losses of water?
Obligatory losses will happen no matter what. Facultative losses will vary with water intake.
What is the normal water turnover for an adult over
24 hours?
The normal water turnover for an adult over 24
hours is 3-4% of total body weight.
What is the normal water turnover for an infant over
24 hours?
The normal water turnover for an infant over 24
hours is ~10% of total body weight.