Body Fluids

Question 1

% Water in Various Tissues

• Skin
• Muscle
• Heart, Liver, Brain, Kidney
• Bone
• Fat (Adipose Tissue)

Answer 1

Skin 70%
Muscle 75%
Heart, Liver, Brain, Kidney 70% - 80%
Bone 25%
Fat (Adipose Tissue) 10%

Question 2

Functions of Body Water

8

Answer 2

• Regulates Body Temperature
• Lubricates Joints
• Flush out waste products (with kidneys and liver)
• Carry nutrients and oxygen to cells
• Moistens tissues (eyes, mouth, nose)
• Protects body organs and tissues
• Helps prevent constipation
• Helps dissolve minerals and other nutrients

Question 3

What are the general trends in variations in body water?

Answer 3

• Fat and Bone cause the most difference
• Fat > Bone

INFANTS

• Have the most body water
• Male and female infants are equal

AT PUBERTY

• less than infant
• females < males

SENIORS

• less than at puberty and infant, drying of tissues
• females < males

Question 4

Obligatory Losses

Answer 4

Insensible - skin and lungs (1 L)

Urine and Stool (0.5L)

Question 5

Faculative Losses

Answer 5

Varies with amount of water intake

Kidney (urine)

Question 6

Water Intake

Answer 6

Oral Fluid (1.2 L)
Oral Food (1.1 L)
Oxidative water from metabolism (0.4L)

Question 7

Water Output

Answer 7

Lungs (0.4)
Skin (insensible 0.5 L)
Kidneys (0.5L obligatory, 1.2 L facultative)
Stool (0.1 L)

Question 8

Insensible Perspiration vs Sweating

Answer 8

INSENSIBLE PERSPIRATION

• Pure water
• Passive evaporation
• Entire skin surface (present even without sweat glands)
• Continuous

SWEATING

• Electrolyte solution
• Active Secretion
• Sweat glands
• Activated by heavy work or high temp

Question 9

Water Turnover in Adults and in Infants

Answer 9

Amount of water going in and out over a 24 hour period.
Adults : 3-4%
Infant: 10%
- infants have a higher surface area to volume

Question 10

Negative Water Balance

Answer 10

Intake < Output
Reduced Intake
Excessive Loss from Gut
Excessive Sweating
Excessive Loss in Expired Air (dry air at high altitudes)
Excessive Loss in Urine (diabetes)

Question 11

Water Intoxication

Answer 11

Intake > Output - causes an electrolyte imbalance
Excessive Intake
Renal System Failure

Question 12

What are the body water compartments?

Answer 12

Intracellular Fluid (2/3 or 40%)
Extracellular Fluid (1/3 or 20%)
- Plasma 5%
- Interstitial Fluid 15%
- Lymph 1 -2% 
- Transcellular Fluid 1%

Question 13

Intracellular Fluid

Answer 13

40% fluid inside all cells

Question 14

Extracellular Fluid

Answer 14

20% fluid outside of cells

Question 15

Plasma

Answer 15

5% fluid component of blood, part of ECF

Blood is 55% plasma and 45% RBC

Question 16

Interstitial Fluid

Answer 16

15% surrounds tissue cells

Question 17

Lymph

Answer 17

1-2% fluid which circulates in lymphatic system, minor part of of ECF

Question 18

Transcellular Fluid

Answer 18

1% aggregate of small fluid volumes secreted by specific cells into a number of body cavities, part of ECF

Question 19

Indicator to measure total body water

Answer 19

Indicator must pass capillary wall and cell membrane

Antipryine, radioactive water

Question 20

Indicator to measure ECF

Answer 20

Indicator must pass capillary wall but not cell memebrane

Inulin, sucrose, mannitol

Question 21

Indicator to measure Plasma

Answer 21

Must not pass capillary wall or cell membrane

Evan’s blue

Question 22

Indicator to measure ICF

Answer 22

Total body water - ECF = ICF

Question 23

Indicator to measure ISF

Answer 23

ECF - Plasma = ISF