Bodily Fluids Flashcards
Between what compartments in the human body is fluid distributed? How does it differ between men and women?
- 55% of female body is fluids; 60% of male body is fluids
- 2/3 of fluid is intracellular, 1/3 is extracellular
- 75% of ECF is interstital, 20% is plasma, 5% transcellular fluid
female has less fluids bc have a higher fat content
transcellular fluid= cerebrospinal fluid, intraocular fluid, gastrointestinal fluid, bile, sweat.
- Fluid that has been secreted but is not in plasma, is seperated by endothelial layerr
- Controlled by secretery cell
What seperates the ICF and ECF?
intracellular fluid (ICF) and extracellular fluid (ECF)
Cell membranes
What seperates interstital fluid and plasma?
Capillary walls
Whats the difference between molarity and molality?
- Molarity (mols solute/ 1L water)
- Molality (mols solute/ 1kg solute)
Molarity= solute & water
Molality= just solute
In a low solute solution is there HIGH or LOW osmotic potential?
HIGH osmotic potential because osmosis is water diffusing from low solute to high solute
In high solute solution there is LOW osmotic potential
What affect does vassopressin/ADH have on body fluid osmolarity?
ADH= antidiuretic hormone= vassopressin
- ADH is released when osmolality is increased or decrease in TBW
- Causes increased water retention
- released by hypothalamic osmoreceptors, which also release thirst signals
TBW= total body water = 0.6x body weight (~42 L)
Increased osmolality/ decreased TBW triggers hypothalamic receptors
This hypothalmus/kidney/thirst mechanism regulates ECF osmolality
What is the Gibbs- Donnan effect?
When there is an unequal distribution of permeable ions across a semi-permeable membrane in the presence of a moleucle that is impermeable
water flows UP osmotic pressure gradient, and Na pump pumps Na out so that cell doesnt explode
What is colloid osmotic pressure?
- Aka oncotic pressure
- osmotic pressure inside the plasma of blood cells
- Caused by proteins (usually albumin) that cant permeate the membrane that binds it
What are the levels of Na+, K+ and Cl- in ECF and ICF?
ICF: LOW Na, HIGH K+, LOW Cl-
ECF: HIGH Na, LOW K+, HIGH Cl-
How would a volume osmolarity diagram change due to dehydration?
Volume decrease and osmolality increase in both ICF and ECF
ECF would decrease from water moving into cells, thus the osmolality would increase from the solutes left behind
Cell is now in a hypertonic soln so water would leave the cell thus raising osmolality
Which way does water move in a…
- hypotonic solution
- hypertonic solution
- isotonic solution
Hypotonic: water moves into cell
Hypertonic: water moves out of cell
Isotonic: no net water movement
Whats the difference between filtration and diffusion?
Both are passive transport
Filtration driven by osmotic pressure
Diffusion driven by solute concentration gradient
Where are AQPI and AQPII found?
AQPI found in most cells
AQPII is only in the kidney collecting duct and is sensitive to ADH
How is cell volume generally controlled?
Cell volume can be regulated by altering the cell’s solute load (osmotically active particles).
Metabolism not only powers solute movement in or out of cell, but affects production/breakdown of polymers (glycogen, proteins) in the cytoplasm.
What does the sodium pump do?
Pumps 3 Na OUT and 2 K IN per ATP
(pumps ions against their conc gradients) (+1 net charge per pump)