25 pages of notes with diagrams. Easy to read and understand. Example of one page: Afferent (sensory): Gets info from the world. Outside of CNS. Signals go up spinal cord Efferent (motor): send neural impulses from CNS to body - muscles Interneurons: neurons which talk to other neurons – memory etc. Types of Glial cells: Support cells • Astrocytes: synchronize the activity of axons o Remove waste material in NS • Microglia: cells that remove waste material from CNS • Suck up bacteria, virus’ Radial glia: provide pathways for neurons to migrate along during development Myelinating glial cells: -involved in myelin production • Olondendrocytes: CNS – envelop more than 1 axons • Schwann cells: PNS – envelop 1 axon Anions: negatively charged Cations: positively charged Float in and out of the neuron Bilipid plasma cell membrane: fat coated cell membrane Sodium (Na+) on outside – wants to come in the cell but cant cos the sodium channels are closed Posassium (k+) on inside of cells Electrochemical gradient: where the charge dictates where the ions should go • E.g. if one side is negative, the electrochemical gradient would ‘pull’ positive ions to the negative side, as positive ions are attracted to negative environment Concentration gradient: the side of the membrane with higher concentration of a certain molecule/ion will lose them down the concentration gradient to the side with the lower concentration of these molecules • The difference in distribution for various ions between the inside and outside of the membrane A Na+/K+ pump pulls Na+ outside the axon membrane, and K+ into it. Free K+ channels allow K+ to go down its concentration gradient, to the outside of the axon membrane. The electrochemical gradient wants the K+ ions to go back into the axon, as the inside is becoming negatively charged with the loss of positive ions. SO K+ goes back in. Action potential: Voltage: Difference in charge between two points Membrane potential: • Rest: -70mV • Threshold = -55 • Action potential = 40 • Threshold for depolarization of membrane necessary to trigger the action potential is -55mV • Action potentials are all or nothing –either get firing of neuron or don’t • If stimulation is sufficient to meet threshold – will get action potential AP stage 1: