Fluid compartments and solutes Flashcards
Under what condition will the volume of a cell change?
If cell membrane is impermeable to certain ions.
What is osmolarity?
Number of solute particles per 1 L of solvent.
What does tonicity take into account?
Osmolarity of impermeable ions.
What is the case of osmolarity in a hypertonic solution?
Osmolarity of impermeable solutes outside of the cell is greater than inside the cell, so cell shrinks.
What is the case of osmolarity in a hypotonic solution?
Osmolarity of impermeable solutes is greater inside the cell than outside the cell and so cell swells.
What is the case of osmolarity in an isotonic solution?
Osmolarity of impermeable solutes inside a cell is the same as outside the cell, so cell volume is unchanged.
Osmolarity of impermeable solutes inside a cell is greater than outside. Why does the cell not burst?
Na+K+ATPase pumps high concentration of sodium ions out of cell to balance high concentration of protein inside the cell.
Purpose of UW solution?
Tissue preservation solution.
What does UW solution contain?
Low Na+ and Cl-. Presence of extracellular impermeable solutes. Presence of macromolecular colloid.
What causes colloid osmotic pressure?
Higher concentrations of plasma protein inside the capillary than outside.
What causes hydrostatic pressure in blood vessel?
Flow of blood.
In a normal blood vessel what is the hydrostatic pressure compared to osmotic pressure?
Hydrostatic is slightly greater allowing solutes to diffuse out of blood vessel. Net leakage of fluid out of capillary.
What is oedema?
Excess fluid loss from capillary into interstitial space.
What can cause hydrostatic pressure to be much greater than osmotic pressure?
Increased pore size in capillary. Plasma protein leaks out of capillary. Concentration gradient is reduced and so osmotic pressure is reduced. Lots of fluid leaks into interstial space leading to oedema.
What is responsible for collecting interstitial fluid?
Lymphatic system.
