Term
| WHAT IS THE NORMAL INTRACELLULAR K+ LEVEL? |
|
Definition
|
|
Term
| WHICH WAY DOES K AND Na MOVE FROM WITHIN THE CELL. |
|
Definition
| THERE IS K EFFLUX AND Na INFLUX DUE TO THE CONCENTRATION GRADIENTS (HIGH TO LOW CONCENTRATION). |
|
|
Term
| IS THE LAW OF ELECTRO NEUTRALITY BROKEN IF I LOSE A POSITIVE CHARGE FROM WITHIN THE CELL THAT MOVED TO THE OUTSIDE? |
|
Definition
| NO. THAT POSITIVE CHARGE DIDN'T DISAPPEAR. IN AN EXAMPLE IT STILL HAS IN THIS CASE +2 AND -2. IT IS JUST THAT THE CHARGES MOVE TO THE OTHER SIDE OF THE CELL MEMBRANE. SO THE LAW OF ELECTRO NEUTRALITY STILL HOLDS. THE ONLY DIFFERENCE IS THAT I AM ESTABLISHING A CHARGE FROM 1 SIDE OF THE MEMBRANE WHICH IS NEGATIVE, WHICJ MEANS THAT THERE WILL BE AND EQUAL AND OPPOSITE CHARGE ON THE OTHER SIDE OF THE MEMBRANE. |
|
|
Term
| WHAT HAPPENS WHEN A POSITIVE CHARGE MOVES OUT THE INSIDE OF THE CELL? |
|
Definition
| THE INSIDE OF THE CELL GETS MORE NEGATIVE. |
|
|
Term
| DESCRIBE THE [ELECTROCHEMICAL] GRADIENT. |
|
Definition
| AN ELECTROCHEMICAL GRADIENT IS THE DIFFERENCE OF ION CONCENTRATION IN 2 POINTS. EX. WE CAN COME TO A POINT AT WHICH THE NEGATIVE CHARGE INSIDE THE CELL IS SO GREAT BECAUSE OF THE LOSS OF K THAT IT IS GOING TO START ATTRACTING THE K BACK IN. OPPOSITE CHARGES ATTRACT. THEREFORE, THE MOVEMENT OF K BACK INTO THE CELL IS BY AN ELECTROCHEMICAL GRADIENT. THAT CAUSE THE K INFLUX (ATTRACTION). |
|
|
Term
| WHAT IS ANOTHER NAME FOR EQUILIBRIUM? |
|
Definition
|
|
Term
| WHEN IS THE POTASSIUM FLUX CONSIDERED AT EQUILBRIUM? |
|
Definition
| WHEN THE AMOUNT THAT IS COMING IN IS EQUAL TO THE AMOUNG THAT IS GOING OUT. |
|
|
Term
| WHAT IS THE CHARGE THAT IS REQUIRED TO START PULLING POSITIVELY CHARGED K IONS BACK INTO THE CELL? HOW CAN THIS BE DETERMINED? |
|
Definition
| WE CAN FIGURE OUT HOW MUCH CHARGE (NEGATVITY) IS REQUIRED TO START PULLING THOSE POSITIVE CHARGED k BACK INTO THE CELL THROUGH THE Nerst EQUATION. E(K+)= (-61/Z)x Log(Ki/Ke). |
|
|
Term
| WHAT ARE THE VALENCES FOR K, NA, CA, CL, AND BICARB? |
|
Definition
| K= +1, Na= +1, Ca= +2, HCO3= -1, Cl= -1 |
|
|
Term
| WHEN WE GET A RESULT FROM Nerst's EQUATION WHAT DOES THAT TELL US? |
|
Definition
| THIS MEANS THAT THE CELL REQUIRES THAT AMOUNT (EX. -96.88mV) OF NEGATIVE CHARGE INSIDE THE CELL TO BALANCE THE CONCENTRATION GRADIENT. |
|
|
Term
| WILL HYPOKALEMIA INCREASE OR DECREASE A CONCENTRATION GRADIENT? |
|
Definition
| INCREASE. (EX. 155-4=151) NOW, (155-2=153). |
|
|
Term
| WHAT DOES IT MEAN IN RELATION TO CHARGES IF YOU INCREASE THE CONCENTRATION GRADIENT? |
|
Definition
| IF I INCREASE THE CONCENTRATION GRADIENT THAT MEANS THAT I REQUIRE MORE NEGATIVE CHARGE. THEREFORE IT LOWERS THE EQUILIBRIUM POTENTIAL. |
|
|
Term
| WHAT DOES HYPERKALMIA DO TO CONCENTRATION GRADIENT AND EQUILIBRIUM POTENTIAL? |
|
Definition
| HYPERKALEMIA REDUCES THE CONCENTRATION GRADIENT (155-9=146) AND ELEVATES THE EQUILIBRIUM POTENTIAL. SO IF WE LOOK AT A NUMBER LINE WITH 0 IN THE MIDDLE AND -96. MOVING TO THE LEFT WOULD BE A REDUCTION IN THE EQUILIBRIUM POTENTIAL. MOVING TO THE RIGHT CAUSES THE EQUILBRIUM POTENTIAL TO RISE. IF THE CONCENTRATION GRADIENT BECOMES SMALLER I DON'T HAVE TO GENERATE THAT MUCH PULL BACK INTO THE CELL. |
|
|
Term
| WHAT WOULD THE EQUILIBRIUM POTENTIAL BE IF EXTRACELLULAR EQUALS INTRACELLULAR? |
|
Definition
| IT WOULD BE 0. THERE IS NO CONCENTRATION GRADIENT. THERE IS NO NET MOVEMENT. WHEN THE CONCENTRATION GRADIENT IS 0 THE EQUILIBRIUM POTENTIAL IS GOING TO BE 0mV. ex. 18/18=1 THE LOG OF 1=0. |
|
|
Term
| WHAT IS A NORMAL INTRACELLULAR NA? |
|
Definition
|
|
Term
| IS THE -61 THAT IS IN THE Nerst's EQUATION A CONSTANT? |
|
Definition
|
|
Term
| WHAT TYPE OF GRADIENT IS RESPONSIBLE FOR NA INFLUX? |
|
Definition
| AN ELECTROCHEMICAL GRADIENT. |
|
|
Term
| DESCRIBE THE REPULSION AND ATTRACTION OF K AND NA. |
|
Definition
| THE NA INFLUX IS DUE TO REPULSION WHEREAS FROM A PREVIOUS EXAMPLE THE K INFLUX WAS DUE TO ATTRACTION(HIGHER CONCETRATION OF NEGATIVE IONS. OPPOSITE CHARGES ATTRACT). THE K INFLUX THAT IS COMING BACK INTO THE CELL WAS DUE TO THE NEGATIVE CHARGE INSIDE THE CELL. THE NA THAT IS LEAVING THE CELL IS BECAUSE THE INSIDE OF THE CELL IS BECOMING MORE POSITIVE AS THE NA TRIES TO COME IN THE POSITIVE CHARGE IS PUSHING IT BACK OUT. |
|
|
Term
| IN TERMS OF - AND + WHAT IS THE EQUILIBRIUM POTENTIAL OF K AND NA? |
|
Definition
|
|
Term
| WHAT DOES HYPONATREMIA DO TO THE CONCENTRATION GRADIENT AND EQUILIBRIUM POTENTIAL? |
|
Definition
| IT DECREASES THE CONCENTRATION GRADIENT. IF I'M COMING IN WITH A BIG CONCENTRATION GRADIENT I NEED A BIG POSITIVE CHARGE TO PUSH IT BACK OUT. BUT IF THE CONCENTRATION GRADIENT GETS REDUCED I NEED A SMALLER OR LESS POSITIVE CHARGE WHICH MEANS THAT A DROP IN THE CONCENTRATION GRADIENT FOR NA RESULTS IN A REDUCTION IN THE EQUILIBRIUM POTENTIAL FOR NA. |
|
|
Term
| WHAT DOES HYPERNATREMIA DO TO THE CONCENTRATION GRADIENT AND EQUILIBRIUM POTENTIAL? |
|
Definition
| IT IS GOING TO INCREASE THE CONCENTRATION GRADIENT. THAT IS GOING TO INCREASE THE EQUILIBRIUM POTENTIAL FOR NA. |
|
|
Term
| WHAT HAPPENS IF YOU COME UP WITH AN EQUILIBRIUM POTENTIAL THAT HAS CAME UP IN THE POSITIVE RANGE? |
|
Definition
| YOU HAVE MESSED UP. REMEMBER IT IS IN/OUT. |
|
|
Term
| WHAT HAPPENS IF YOU HAVE A BIGGER CONCENTRATION GRADIENT LIKE +65? |
|
Definition
| IT REQUIRES MORE + CHARGE INSIDE THE CELL TO REPEL THE CONCENTRATION GRADIENT. THEREFORE, BY ALTERING THE EXTRACELLULAR K AND ALTERING EXTRACELLULAR NA WE CAN ALTER THE EQUILIBRIUM POTENTALS FOR THESE. |
|
|
Term
|
Definition
| A NON GATED CHANNEL THAT IS ALWAYS OPEN. THEY ARE ELECTROSPECIFIC. |
|
|
Term
| ARE THE AMOUNT OF NA AND K LEAK CHANNELS IN A CELL EQUAL? |
|
Definition
| NO! THERE ARE MORE K LEAK CHANNELS. |
|
|
Term
| HOW DO WE FIND A CHARGE INSIDE A CELL IF WE HAVE AN EXAMPLE OF -96 K AND +65 NA? |
|
Definition
| WELL THE LEAK CHANNELS ARE NOT EQUALS SO WHAT WE ARE LOOKING FOR NOW IS NO LONGER THE EQUILIBRIUM POTENTIAL, BUT THE RESTING MEMBRANE POTENTIAL. |
|
|
Term
| IS THE RESTING MEMBRANE POTENTIAL OF A CELL + OR -? |
|
Definition
| NEGATIVE, THEREFORE WE HAVE MORE WEIGHT ON THE K THEN NA. |
|
|
Term
| WHAT IS THE FORMULA FOR CONDUCTANCE RATIO? |
|
Definition
| (Gk/Gmem) Mem= membrane which is the total of everything moving out. |
|
|
Term
| IF A CONDUCTANCE RATIO OF K WAS 0.8 WHAT IS THE CONDUCTANCE RATIO OF NA? |
|
Definition
| 0.2. IT IS A PERCENTAGE SO IT IS EQUAL TO 100% OR 1. |
|
|
Term
| WHAT IS THE FORMULA FOR THE GHF RMP? |
|
Definition
| RMP= (Ek)X (Gk/Gmem) + (Ena) x (Gna/Gmem) |
|
|
Term
| HOW DO WE GET A TRUE RMP? |
|
Definition
| IT IS A FUNCTION OF K LEAK CHANNELS, NA LEAK CHANNELS, AND NA/K ATPASE. SIMPLE ENOUGH WE JUST SAY (-4MV). |
|
|
Term
| WHAT IS THE REASON THAT IF YOU CHANGE THE EXTRACELLULAR K RATHER THAN NA YOU GET A BIGGER CHANGE IN THE ELECTROCHEMICAL GRADIENT? |
|
Definition
| K WEIGHS MORE. THERE ARE MORE K LEAK CHANNELS. WHEN WE ARE LOOKING AT HYPO OR HYPOERNATREMIA IT REQUIRES A MUCH HIGHER CHANGE IN EXTRACELLULAR NA TO START CAUSING PROBLEMS LIKE MUSCLE CRAMPS OR ARRHYTHMIAS. |
|
|
Term
| DESCRIBE CELLS THAT HAVE A RMP AND CELLS THAT DON'T. |
|
Definition
| FOR CELLS THAT HAVE A RESTING MEMBRANE POTENTIAL THE MEMBRANE CONDUCTANCE ARE CONSTANT. THEY ARE CONSTANT UNTIL THEY GET STIMULATED. ON THE OTHER HAND, AN SA NODE IS CONSTANTLY ACTIVE BECAUSE THEY DON'T HAVE A RMP. |
|
|
Term
| WHAT ARE GRADED POTENTIALS GENERATED BY? |
|
Definition
|
|
Term
| WHAT DETERMINES IF SOMETHING COMES IN VS OUT OF THE CELL? |
|
Definition
| THE CONCENTRATION GRADIENT AND THE CHANNEL ITSELF |
|
|
Term
| WHAT IS GOING TO HAPPEN TO A LIGAND GATED CHLORIDE CHANNEL? |
|
Definition
|
|
Term
| WHAT DOES THE CHANNELS AND LIGATED GATED CHANNELS DO WHEN AT REST? |
|
Definition
| THE LEAK CHANNELS ARE OPEN AND THE LIGAND GATED CHANNELS ARE CLOSED. |
|
|
Term
| DEALING WITH A MEMBRANE POTENTIAL GRAPH WHAT IS THE X AND Y AXIS STAND FOR? |
|
Definition
|
|
Term
| WHAT HAPPENS TO THE CELL AT RMP? |
|
Definition
| IT IS AT REST, IT IS DOING NOTHING, THE CHARGE DOESN'T CHANGE, IT STAYS THE SAME. |
|
|
Term
| WHAT IS THE THRESHOLD NUMBER? |
|
Definition
|
|
Term
| WHAT IS IT CALLED WHEN YOU ARE MOVING CLOSER TO A THRESHOLD? |
|
Definition
| EPSPs. excitatory post synaptic potential |
|
|
Term
| WHAT ARE THE 2 TYPES OF GRADED POTENTIALS? |
|
Definition
|
|
Term
| WHAT 2 THINGS GENERATE A EPSP? |
|
Definition
| CATION INFLUX AND ANION EFFLUX |
|
|
Term
|
Definition
| IT MOVES DOWN THE GRAPH AWAY FROM THE THRESHOLD POTENTAL. |
|
|
Term
| WHAT 2 WAYS CAN WE GENERATE IPSP? |
|
Definition
| ANION INFLUX AND CATION EFFLUX |
|
|
Term
| WHAT DETERMINES WHEATHER THE CELL MOVES FROM THE RMP TO THRESHOLD OR NOT? |
|
Definition
| THE INFLUX OR EFFLUX OF CATION AND ANION. |
|
|
Term
| WHAT IS GOING TO HAPPEN IF WE HAVE MORE EPSP THAN IPSP? |
|
Definition
| YOU *MAY* REACH THRESHOLD. |
|
|
Term
| IF I HAVE MORE IPSP THEN EPSP WHAT WILL HAPPEN? |
|
Definition
| THRESHOLD WILL *NEVER* BE REACHED. |
|
|
Term
|
Definition
| THE 2 WAYS OF ADDING UP EPSPs and IPSPs. |
|
|
Term
| WHAT 2 WAYS CAN GRADED POTENTIALS BE IN? |
|
Definition
| SPATIAL (SPACE) OR TEMPORAL (TIME) |
|
|
Term
| GIVE AN EXAMPLE OF TEMPORAL SUMMATION. |
|
Definition
| LET'S SAY WE NEED 5 NA IONS TO COME INTO A CELL. THERE ARE 2 WAYS THAT I AN DO IT. I CAN TAKE 1 CHANNEL (NA COMES IN THEN GOES AWAY X5 TIMES), BUT IT TAKES TIME. THIS IS AN EXAMPLE OF TEMPORAL SUMMATION. TEMPORAL SUMMATION OCCURS ON TOP OF EACH OTHER. |
|
|
Term
| GIVE AN EXAMPLE OF SPATIAL SUMMATION. |
|
Definition
| INSTEAD OF HAVING 1 LIGAND GATED NA CHANNEL WHAT HAPPENS IF WE HAVE 5 OF THEM. THEY ALL BIND AT THE SAME TIME WHICH LETS 1 NA MOLCULE TO COME IN AND THEN THEY CLOSE. SO WE NOW HAVE A SPATIAL SUMMATION. |
|
|
Term
| DOES SPATIAL AND TEMPORAL SUMMATION OCCUR AT THE SAME TIME? |
|
Definition
|
|
