nervous system mas maganda
TRANSCRIPT
Nervous system
Action potential
Caused by voltage difference across the plasma membrane
Due to ionic composition Inside: more K+ than Na+
Outside: more Na+ than K+
Anions: primarily inside and composed of large molecules
Channels
Channels are responsible for the permeability of the membrane Voltage-gated ion channels Chemically-gated ion channels
Propagation of AP
Neuron is stimulatedVoltage-gated ion channels will openK will move outside due to conc gradientWill return due to electrical gradientNa reverse reaction of KResting membrane potential of -70mV
rather than -85mV
REMEMBER!!!!!!!!!!!!!!!
Dissipation of membrane potential is hindered due to the presence of the sodium potassium pump
The very important graph
The very important terms……
Polarization- creation of different charges inside/outside the cell membrane
Depolarization- membrane is more positive (dec in electrical gradient)
Hyperpolarization- membrane is more negative (inc electrical gradient)
Terms pa rin……..
Threshold potential- amount of potential difference needed to create an action potential
Action potential- electrical stimulus that creates signal/message in an axon
Hyperpolarization- do not produce action potential
Graded potential if it is dependent on the amount of stimulus
Action potential in case of neurons that need to meet the threshold potential
AP is the nerve impulse
TANDAAN!!!!!! Nongraded all or none response/event
Ang pagbabalik…….
Ano ba nangyayari?
Start with voltage-gated ion channel K- one gate; closed-resting, opens slowly during
depolarization Na- two gates; activation gate- closed-resting, opens
rapidly during depolarizationinactivation gate- open when resting, closes
slowly due to depolarization
Huh?
K is responsible for hyperpolarization because they remain open during repolarization
Na is responsible for depolarization
synapse
VoltageChemical
EPSP vs IPSP
Excitatory postsynaptic potentialInhibitory postsynaptic potential
Temporal vs summation
Magbasa……..
Magbasa ng mga neurotransmitter at different kinds ng organization of nervous system
Hyperpolarization
Responsible for the unidirectional movement of the action potential