Fluid compartments Flashcards
What are the approximate proportions of fluid in th ebody
60pc water
- 55pc of this is IC
- 45pc is EC
- -36pc is IF
- -7pc blood plasma
- -2pc is transcellular - CSF, SYNOVIAL
How doe spH differ in plasma compared to intracellular
plasm 7.4
muscle 7.1
How are fluids characterised
IF is in BASAL extracellular space
Blood is PLASMA
other is Extracellular fluid
What is osmolarity?
Measure of concentrations of ALL SOLUTES in solution
Why i sosmolarity weak?
Doesn’t consider membrane permeability
What is tonicity?
Measure of both membrane permeability and solution composition
What do iso, hypo and hpyer tonic mean?
Isotonic is where tonicity - osmolarity of impermeant solution son in and out is the same,
Hypotnoic is where its less than out, so it swells
Vv for hyper
How do cells ensure they don’t burst or shrink?
Sodium potassium pump, so internal and external osmolarities of impermeant solutes are balanced.
What is membrane perm and imperm to
Perm
- hydrophobic
- some small
imperm
- large uncharged polar
- ions
What are the methods of membrans crossing
Passive
- simple diff
- fac diff via channel protein - voltage
- carrier protein - conformational change
active
- against conc grad
- endo, exocyt
How are substrates exchanged across capillary wall?
Lipid solube straight through
Water soluble go through pores
Proteins by vesicles
plasma proteins too big
What is oedema
Excess intersitial fluid by HP»>OP
LAck of draingae from lymphatic
leads to accumulation of fluid
caused by hypertsension, inflammation
