PS263 Lecture Notes - Lecture 3: Sodium-Potassium Alloy, Excitatory Synapse, Resting Potential
Document Summary
Covers, the axon except at nodes of ranvier. The cover of the myelin is not continuion, there are gaps. When an axon is covered by mylein ions are blocked and cannot come in and out. Due to this we get action potentials in the gaps but not in the parts covered in myelin because they cannot get in. This is called saltatory conduction - its a lot faster than conducting a signal along a neuron. Neurons at a rest have -ve membrane potential of about -70mv. Na channels close; k exists and na/k pump restores resting potential. Where the action is, where all the interesting things happen. Where 2 neurons connect neurons can have lots of axons. Require a different form of communication primary form of communication is chemical (not electric) Pre- and postsynaptic cells do not touch the gap is called the synaptic cleft. Presynaptic cell releases chemicals (neurotransmitters) that affect the postsynaptic cell.