HMB200H1 Lecture Notes - Lecture 3: Potassium Channel, Sodium Channel, Sensory Neuron
Document Summary
The brain/city analogy analogy to simple reflex: parallel and hierarchical structures (cortex, hippocampus/library) provide higher level processing functions to modify the output. Perceptual world created from sensory receptors translated to the language of the cns: electrical languages action potentials, every sensory organ system has uniquely tuned neurons/ nerve endings to sense stimulus. Sensory signals activate sensory receptors: within the neurons in somatosensory system, there are proteins called ion channels, stretch sensitive ion channels. Ion channels examples and properties: when channels open, they become permeable to ions, more than a thousand different ion channels in mammals, properties each channel has unique. Dynamics (how it opens/closes, how long, etc) Means of activation (sensory, ligand, voltage, etc) Ion flow can cause voltage changes: you can get charged changes depending on which ions flows. Signaling in neurons: example: sensory input opens channels for certain ions from stimulus. Na channels activated and allowed to enter changes the charge distribution (voltage) locally.
