Electrophysiology WK5 L1 Flashcards
WHAT IS ELECTRICAL POTENTIAL?
WHAT IS THE ELECTRICAL CURRENT?
THW FLOW OF THE CHARGED PARTICLES FROM ONE POINT TO ANOTHER
ARE LIVING CELLS POLARIZED?
YES
WHAT IS THE RESTING MEMBRANE POTENTIAL?
-70 mV WITH A NEGATIVE CHARGE ON THE INSIDE OF THE MEMBRANE WHEN THINGS ARE AT REST
IS THE MEMBRANE VERY PERMIABLE TO K+ OR Na-?
K+
WHAT DOES THE SODIUM (Na-) / POTASSIUM (K+) PUMP DO WHEN IT IS AT REST?
PUMPS PUT 3X Na- FOR EVERY 2X K+ IT BRINGS IN USING ATP
WHAT IS LOCAL POTENITALS?
SMALL CHANGE IN VOLTAGE ALONG ONE SPOT IN THE MEMBRANE
WHEN DOES LOCAL POTENTIALS OCCUR?
WHEN NEURONS ARE STIMULATED BY CHEMICALS - LIGHT - HEATS - MECHANICAL DISTURBANCES
WHAT IS THE CHANGE IN VOLTAGE CALLED?
DEPOLARISATION
WHAT IS DEPOLARISED?
MOVING TOWARDS 0 (EQUAL CHARGED) FROM A HIGHER CHARGE LEVEL
WHAT IS POLARISED?
MOVING AWAY FROM 0 (EQUAL CHARGE) TO A HIGHER CHARGE
HOW DOES DEPOLARISATION DECREASE POTENTIAL?
SODIUM CHANNELS OPENING SO SODIUM CAN CROSS THE MEMBRANE FROM HIGH TO LOW CONCENTRATION
WHEN ARE THE SODIM CHANNELS CLOSED?
AT REST
WHAT IS ACTION POTENTIAL?
CHANGE IN THE VOLTAGE INT HE MEMBRANE AT A LOCAL SPOT
WHAT IS ACTION POTENTIAL?
CHANGE IN THE VOLTAGE IN THE MEMBRANE AT A LOCAL SPOT CAUSING DEPOLARIZATION AND REPOLARIZATION
WHAT IS THE THRESHOLD POINT?
-55 mV
WHAT HAPPENS WHEN WE MEET THE THRESHOLD VOLTAGE?
LOTS OF SODIUM CHANNELS OPEN AND MASSIVE AMOUNTS OF SODIUM RUSH INTO THE CELL MAKING THE CELL MORE POSITIVELY CHARGED
WHAT IS REPOLARIZATION?
WHEN THE POTASSIUM CHANNELS SLOWLY OPEN RELEASING POTASSIUM OUT OF THE CELL WHICH MAKES THE CELL MORE NEGATIVELY CHARGED
WHAT IS HYPER-POLARIZATION?
WHEN THE POTASSIUM CHANNELS RELEASE SO MUCH SODIUM OUT OF THE CELL LEAVING THE CELL MORE NEGATIVELY CHARGED THAN IT WAS PREVIOUSLY
WHAT IS THE REFRACTORY PERIOD?
THE PERIOD OF RESISTANCE TO STIMULATION (COOL DOWN PERIOD BETWEEN ACTION POTENTIALS)
WHAT IS THE ABSOLUTE REFRACTORY PERIOD?
PERIOD WHERE THE SODIUM CHANNELS CLOSE DURING DEPOLARIZATION AND WILL NOT START AN ACTION POTENTIAL NO MATTER HOW MUCH STIMULI IS GIVEN
WHAT IS THE RELATIVE REFRACTORY PERIOD?
STIMULUS CAN CREATE AN ACTION POTENTIAL IF THE POTASSIUM CHANNELS ARE OPEN
WHAT IS AN INHIBITRY SYNAPSE?
WHEN CHLORIDE ANIONS MOVE INTO THE CELL MAKING IT MORE NEGATIVELY CHARGED AND HYPERPOLARIZING THE CELL
WHAT ARE THE STEPS OF CESSATION OF SIGNAL
DIFFUSION - ENZYMATIC DEGRADATION - REUPTAKE OF NEUROTRANSMITTER
WHAT IS DIFFUSION?
SOME OF THE NEURTOTRANSMITTER MOLECULES DIFUSE AWAY FROM SYNAPTIC CLEFT
WHAT IS ENZYMATIC DEGRADATION?
ENZYMES BREAK DOWN NEUROTRANSMITTERS
WHAT IS REUPTAKE OF NEUROTRANSMITTERS?
MANY NEUROTRANSMITTERS ARE ACTIVELY TRANSPORTED BACKT O THE PRESYNAPTIC NEURON BY ENDOCYTOSIS
WHAT ARE THE TYPES OF NEUROTRANSMITTERS?
ACETYCHLOLINE - AMINO ACID NEUROTRANSMITTERS - MONOAMINES - NEUROPEPTIDES
WHAT IS ACETYCHLOLINE?
NEURO TRANSMITTERS FOR THE MUSCLES AND PERIPHERAL NERVOUS SYSTEM
WHAT ARE AMINO ACID NEUROTRANSMITTERS?
NEUROTRANSMITTERS IN THE BRAIN - EXCITATORY (GLUTAMATE) AND INHIBITORY (GABBA)
WHAT ARE MONOAMINES?
MODIFIED AMINO ACIDES
WHAT ARE NEUROPEPTIDES?
PROTEIN NEUROTRANSMITTERS IN THE NERVOUS SYSTEM
