water if life Flashcards
Which 2 processes are regulated towards maintaining H2O balance
- Input is regulated by the thirst mechanism
- Output by regulation of urinary losses
What does every cell in our body need in order to survive
oxygen and food
Internal environment
optimum environment for all cells to function
What is the fluid which bathes each of the body’s cells
Extracellular fluid (ECF)
The fluid inside all of the cells of the body
Intracellular fluid (ICF)
What is total body water (TBW) split between
Intracellular fluid + Extracellular fluid
What is ECF made up of
interstitial fluid + plasma
What is exchanged by interstitial fluid
oxygen, CO2, nutrients and waste
Which 2 compartment is ECF split into
- 80% surrounds the body cells - Interstitial fluid (ISF)
- 20% constitutes the fluid portion of the blood - Plasma
Plasma
- Continuously circulated to all parts of the body by the action of the heart
- Continuously refreshes the cells by bringing fresh O2 and nutrients and removing CO2 and waste
What does plasma exchange with ISF
nutrients and waste
When does exchange occur
As blood passes through the capillaries of the body
What is the movement across the capillary walls like
Free movement, except for plasma proteins which are too large and are restricted to plasma
What kind of mixture is ECF
Homogeneous
Distribution of body water
- ECF - 1/3 (roughly 14L in average man)
- ICF - 2/3 (roughly 28L in average man)
