Tissues 5 Flashcards
How much of a person is water?
60%
How much of the water content is intracellular?
55%
How much of the water content is extracellular?
45%
Describe the composition of body water.
Interstitial fluid - 36%
Blood plasma - 7%
Transcellular fluid - 2% (eg CSF)
Where is more Na found?
Extracellularly
Where is more K found?
Intracellularly
Where is more Ca found?
Extracellularly
Where is more Cl found?
Extracellularly
Whats the difference between plasma and interstitial fluid?
Plasma has more protein
Where are more protein anions found?
Intracellularly
Why is intracellular pH lower?
H+ conc is greater there.
Osmolarity of all cells is same outside as inside. Why?
To prevent osmotic damage
What is osmolarity?
Measure of all solute particles in a solution
Why isn’t osmolarity a good guide of the effects of cell volume?
Doesn’t depend on cell permeability
What is tonicity?
Defines strength of a solution as it affects final cell volume
Depends on both membrane permeability and solution composition
Hypertonic?
Outside impermeant solutes greater than intracellular solutes.
Cell shrinks
Hypotonic?
Intracellular impermeant solutes greater than extracellular
Cell swells
Isotonic?
Osmolarity of impermeant solutes equal either side of the membrane.
Cell remains the same
In reality, why do cells not burst?
Presence of Na/K pump on all cell membranes.
Maintains Na conc lower inside the cell than outside
When tissue fluid is released, where do lipid soluble molecules diffuse out of?
The endothelium of the capillaries.
What do pores in the capillary wall allow?
Exchange of water and water soluble molecules.
Name 3 causes of oedema
Inflammation, trauma, hypertension
