Lab Exam 1 Osmosis/ActionPotential Flashcards
Osmosis
Osmosis - net diffusion of water from an area of higher concentration to lower concentration
(hypotonic to an area of hypertonic)
osmolality(Osm)
osmolality(Osm) - the concentration of a solution in terms of osmoles of solutes per kilogram
Osmolitcally Active
Osmolitcally Active - if a solute like salt is stuck on one side and cannot freely move across the membrane it is osmotically active
Tonicity
Tonicity - is a question: will there be NET diffusion of H2O across a semi permeable membrane
Isotonic
Isotonic - No net water movement. i.e. Normal Saline
NaCl:
NaCl: 58 grams -> 1 mole -> 1 molal (M) -> 2 osmolal (Osm) -> 2000 milliosmolal (mOsm)
NS
NS: 9 grams -> 0.15 mole -> 0.15 molal (M) -> 0.3 osmolal (Osm) -> 300 milliosmolal (mOsm)
Glucose
Glucose: 180 grams -> 1 mole -> molal (M) -> 1 osmolal (Osm) -> 300 milliosmolal (mOsm)
blood osmolality
blood osmolality = 280 to 300 mOsm/Kg
Osmosis occurs from a hypotonic to a hypertonic solution
behavior of cells in solutions with different tonicities
isotonic solution
isotonic solution - normal saline = happy cells
behavior of cells in solutions with different tonicities
hypotonic solution
behavior of cells in solutions with different tonicities
behavior of cells in solutions with different tonicities
hypertonic solution
hypertonic solution - cell rapidly leaves the cell causing it to crenate or shrinks
Rising phase
Rising phase - Na+ entry/depolarization
falling phase
falling phase - K+ exit/repolarization
after-hyperpolarization
after-hyperpolarization - K+ continues to exit until NA+/K+ pump turns on
graded potential
graded potential - initial wave due to NA+ ligand gated entry. it can be anywhere from -70 -> -54mV
action potential
action potential - wave of unstoppable depolarization when the cell raches -55mv
hyperkalemia
hyperkalemia - flaccid paralysis. RMP rises past -55mv. to where the gates never close and there is a continuous AP
hypokalemia
hypokalemia - muscle weakness, low RMP. goes from -70 to lets say -90mv. it makes it impossible for a graded potential to hit -55mv and an AP will never happen
hypernatremia
hypernatremia- cell will beome more positive and the peak of the AP will be higher
hyponatremia
hyponatremia - can be caused when you drink too much water. no affect on RMP but the peak will be lower
TTX(Tetrodotoxin)
TTX(Tetrodotoxin) - blocks sodium channels and causes paralysis, No AP. Used at the dentist to numb
TEA
TEA - neurotoxin that does not allow the cell to repolarize
Absolute refactory period
Absolute refactory period - the time where if another stimulus were given to a cell it would not lead to a second AP
relative refractory period
relative refractory period - during after polarization, a cell could send another AP if the stimulus was strong enough
the more NT is between the synapse
the longer and stronger and more frequent an AP will be