BODY FLUIDS WITH VERIFIED
AND ACCURATE ANSWERS
GRADED A+ (2026)
Body Water Content - answer-• Infants are 73% or more water (low body fat, low bone
mass)
• Adult males: ~60% water
• Adult females: ~50% water (higher fat content, less skeletal muscle mass)
- Adipose tissue is least hydrated of all
- Total body water in adults averages ~40 L
• Water content declines to ~45% in old age
Two main fluid compartments - answer-Intracellular fluid (ICF) - fluid inside cells
accounts for 2/3 of total body fluid
Extracellular fluid (ECF) - fluid in 2 main ECF compartments outside cells accounts 1/3
total body fluid
Composition of BODY FLUIDS - answer-- water is the universal solvent
- solutes substances dissolved in water
- solutes are classified as non-electrolytes ( most organic molecules) and electrolytes
Electrolytes - answer-- dissociate into ions in water
, - ions conduct electrical current
- electrolytes are most abundant ( largest# ) solutes in body fluid , determine most
chemical and physical reactions
- greater osmotic power than non-electrolytes , greater ability to cause fluid shift due to
ability to dissociate into 2 ions or more
COMPARISON OF ECF AND IFC
( open ended ) - answer-ECF: electrolyte contents are all similar except for higher
protein , lower CL- content of plasma
ICF: contains more soluble proteins than plasma
( bulk of dissolved solutes consists of proteins , phospholipids, cholesterol and
triglycerides )
90% IN PLASMA
60% IN IF
97% IN ICF
Fluid Movement Among Compartments - answer-- regulated by osmotic and hydrostatic
pressures
- water moves freely by osmosis
- change in solute concentration of any compartment leads to net water flow
Rise in ECF OP (osmotic pressure) = H2O leave cell
vise versa
AND ACCURATE ANSWERS
GRADED A+ (2026)
Body Water Content - answer-• Infants are 73% or more water (low body fat, low bone
mass)
• Adult males: ~60% water
• Adult females: ~50% water (higher fat content, less skeletal muscle mass)
- Adipose tissue is least hydrated of all
- Total body water in adults averages ~40 L
• Water content declines to ~45% in old age
Two main fluid compartments - answer-Intracellular fluid (ICF) - fluid inside cells
accounts for 2/3 of total body fluid
Extracellular fluid (ECF) - fluid in 2 main ECF compartments outside cells accounts 1/3
total body fluid
Composition of BODY FLUIDS - answer-- water is the universal solvent
- solutes substances dissolved in water
- solutes are classified as non-electrolytes ( most organic molecules) and electrolytes
Electrolytes - answer-- dissociate into ions in water
, - ions conduct electrical current
- electrolytes are most abundant ( largest# ) solutes in body fluid , determine most
chemical and physical reactions
- greater osmotic power than non-electrolytes , greater ability to cause fluid shift due to
ability to dissociate into 2 ions or more
COMPARISON OF ECF AND IFC
( open ended ) - answer-ECF: electrolyte contents are all similar except for higher
protein , lower CL- content of plasma
ICF: contains more soluble proteins than plasma
( bulk of dissolved solutes consists of proteins , phospholipids, cholesterol and
triglycerides )
90% IN PLASMA
60% IN IF
97% IN ICF
Fluid Movement Among Compartments - answer-- regulated by osmotic and hydrostatic
pressures
- water moves freely by osmosis
- change in solute concentration of any compartment leads to net water flow
Rise in ECF OP (osmotic pressure) = H2O leave cell
vise versa
