Anatomy ch 7.2

• Graded potential occurs in receptive segment of the neuron due to opening of chemically gated channels
• Postsynaptic potentials contains graded potentials
• Action potentials is generated at the axon hillock. The RMP much reach a threshold of -55mV
• Neurotransporter binds to sodium or chloride channels which will increase or decrease the charge
• Excitation postsynaptoc potentials os EPSP increase the likelihood of an action potential from occurring by increasing the value and getting closer to the threshold
• Inhibitory synaptic potentials or IPSPS decrease likelihood of action potential by decreasing the charge. Located along initial segment
• UPSO and ESPSP are added in the axon hillock to determine mV
• In the initial segment, sodium voltage gated channels are opened and once 30mV is reached, sodium channels will deactivate and will open potassium channels to repolorize the cell. The cell will reach -80mV and will slowly return at RMP during the state of hyperpolarization
• In the conductive segment the action potential will open sodium channels to depolarize the cell until 30mV. Potassium channels then open up and bring the charge down in the process called repolarization. Potassium remain open longer than needed and slowly go up to MRP in state called hyperpolarization
• In the refractory period, the time to start action potential is either difficult or impossible
• In the transmission segment, the signal can run either continously or saltatorily
• In the transmission segment, the change in V will open calcium channels to let them in and bind to vehicles. The calcium will push the vesicle to the synaptic know end and push it out via exocytosis. Calcium pumps will then pump calcium out and restores calcium concentration outside the wall