BIOL 111 Lecture Notes - Saltatory Conduction, Threshold Voltage, Action Potential

• School: McGill University
• Department: Biology (Sci)
• Course: BIOL 111
• Professor: Andrew Hendry

Document Summary

Specialization of neurons: bushy dendrites collect info from many other cells (cerebellum: purjinke cell, neurons with fewer dendrites process few inputs (retina: bipolar cells, cerebral cortex (pyramidal cell): loooong axon for communication and branch over large area. Parts of nervous system: neurons: generate + transmit electrical signals, glial cells (more numerous): Modulate info transmission: glial cells in pns: schwann cells produce myelin. Faster transmission b/c signals jump from nodes of ranviers. Neurons work electrochemically: animal cells: more k+ inside and na+ extracell. Maintain concentration grads (more k+ in, na+ out) Ion selective channels open: ions follow electrochem gradient to reach equilibrium potential (no. Gated by voltage, mechanically, chem. (neurotransmitters: changing membrane potential. Gated ion channels cause changes: resting potential: only k+ leak channels open, na+ channels open: depolarization b/c inside less ve relative to outside, na+ channels close, gated k+ channels open: hyperpolarization (huge shift of +ve charges outside)