Body Fluids Flashcards
(41 cards)
What is the function of water?
- medium for all metabolic processes
- diffusion of nutrients and waste products
- solvent
- homeostasis
What is the consequence of having too little water in the body?
Diarrhoea and very low blood pressure - 90/40mmHg
What is the consequence of having too much water in the body?
Kidney failure and very high blood pressure- 200/100mmHg
If there was an intake of 2300ml of water, what would it be used for?
Ingested= 2100ml Metabolism= 200ml
If there was an output of 2300ml of water, what would it be used for?
Urine= 1400ml Loss from skin= 350ml Loss from lungs= 350ml Faeces= 100ml Sweat= 100ml
Where can fluid be found inside the body?
Inside cells, interstitial fluid or blood plasma
The body is 60% water, how much of that forms the intracellular and extracellular fluid?
Intracellular= 40% Extracellular= 20%
Why is the composition of body fluids in each compartment different?
As each compartment has different ions
Which ions does the intracellular compartment contain?
Potassium and phosphate ions
Which ions does the interstitium contain?
Sodium and chloride ions
Which ions does the blood plasma contain?
Sodium and chloride ions
What is the difference between the permeability of the capillary membrane and the plasma membrane?
Capillary membrane is more permeable than the plasma membrane. Plasma membrane only allows specific molecules to pass through
Which molecules does the plasma membrane allow through?
Sodium, chloride, potassium and phosphate ions
Which ions are found inside and which are found outside of the cell?
Inside= potassium and phosphate ions Outside= sodium and chloride ions
What regulates the concentration of sodium and potassium ions and how?
Na+/K+ pump, 3 sodium ions pumped out, 2 potassium ions pumped in
What do fluid movements depend on?
Ionic and osmotic pressure and the nature of the barrier
What drives the movement of water in and out of the cell membrane?
Osmotic pressure
What is the structure of the capillary wall barrier?
It has endothelial cells and are separated by semi-permeable pores
What drives the movement of water in and out of the capillary wall barrier?
Hydrostatic pressure
What is the definition of osmosis?
The net diffusion of water across a selectively permeable membrane from a region of high water potential to a region of low water potential
What is the unit of measurement of osmosis?
An osmole
What does an osmole describe?
The concentration of solute particles in a solution
What is 1 osmole equal to?
1 osmole= 1 mole= 6x10^23 osmotically active particles
What is osmolality?
Osmole/kg of solvent