Physiology 1 Flashcards
what is osmolarity?
concentration of osmotically active particles present in a solution
osmolarity units?
osmol/l or mosmol/l
what 2 things must you know to calculate osmolarity?
solution molar concentration
number of osmotically active particles present
what is the osmolarity of a 150mM molar concentration of NaCl?
2 (1 from Na and 1 from Cl) x 150 = 300mosmol/l
osmolality units?
osmol/l
osmolarity and osmolality are interchangeable for weak salt solutions
________ is the effect a solution has on cell volume
TONICITY is the effect a solution has on cell volume
name the 3 different possible tonicities of a solution
isotonic
hypotonic
hypertonic
state what happens to a cell in the following:
(a) hypertonic
(b) isotonic
(c) hypotonic
(a) hypertonic - CELL SHRINKS
(b) isotonic - RBC
(c) hypotonic - CELL LYSIS
hypertonic solutions have ____ water and regarded as a concentrated ____ solution
hypertonic solutions have LESS water and regarded as a concentrated SALT solution
hypotonic solutions have _____ water
hypotonic solutions have MORE water
who has more TBW, males or females?
males
females have more fat
TBW exists as how many major compartments?
name them
2
intracellular fluid (ICF) extracellular fluid (ECF)
what makes up extracellular fluid?
plasma (20%) and interstitial fluid (80%)
how can we measure body fluid compartments?
tracers
name the useful tracers for the following:
(a) TBW
(b) ECF
(c) plasma
(a) TBW - 3H2O
(b) ECF - inulin
(c) plasma - labelled albumin
TBW = ? + ?
TBW = ECF + ICF
what equals dose/sample concentration?
volume
Qx (mol) / [X] (mol/litre) is the equation for that?
distribution volume
name some inputs of fluid into the body
fluid intake
food intake
metabolism
name some outputs of fluid out of the body
skin lungs sweat faeces urine
name the ions in the following compartments:
(a) ICF
(b) ECF
(a) ICF - K+
(b) ECF - Na+ and Cl- and HCO3-
cell membranes are ____________ permeable
cell membranes are SELECTIVELY permeable
osmotic concentrations of both ECF and ICF are ___________
osmotic concentrations of both ECF and ICF are IDENTICAL
movement of water between the ICF and ECF in response to an osmotic gradient defines what?
fluid shift
gain or loss - ECF NaCl gain:
(a) ECF
(b) ICF
gain or loss - ECF NaCl gain:
(a) ECF increase
(b) ICF decrease
gain or loss - ECF NaCl loss:
(a) ECF
(b) ICF
gain or loss - ECF NaCl loss:
(a) ECF decrease
(b) ICF increase
in the gain of a isotonic fluid, there is only a change in the ___ volume only
in the gain of a isotonic fluid, there is only a change in the ECF volume only
what organ alters composition and volume of ECF?
kidney
changes in {K+]plasma can result in what 2 serious consequences?
paralysis and cardiac arrest
what follows salt?
water follows salt