PSYX 100 1st Edition Lecture 7 Outline of Last Lecture I Quiz Retakes Outline of Current Lecture I Biological Psychology II The Neuron III Neural Communication IV Receiving Messages V Action Potential VI Myelin Sheath Current Lecture I II Biological Psychology a Describes the connection between biology and behavior b Also called biopsychology psychobiology physiological psychology and behavioral neuroscience The neuron a Basic unit of communication in the nervous system b The neuron receives integrates and sends information c Soma of a neuron i Contains the cell nucleus ii Is the brain of the cell that holds the chemicals and directions for the neuron d Dendrite of a neuron i Parts of the neuron that receives information ii Have a branched structure e Axon of a neuron i Part of the neuron that sends information to other neurons muscles or glands ii Ends in a cluster of terminal buttons 1 Terminal buttons are small knobs that secrete chemicals called neurotransmitters These chemicals serve as the messengers f Myelin sheath i Most neurons are wrapped in myelin sheath These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute III IV V VI ii It is a white fatty substance that insulates the axon and increases the speed of transmission signals g Glia cells i Cells that provide support for neurons ii They nourish remove waste from and insulate neurons Neural Communication a Discovered by Alan Hodgkin and Andrew Huxley while they were studying axons in squids b Neural communication is a complex electrochemical process c Neural communication uses energy to send information in the form of neural impulses d Resting potential the stable negative charge in an inactive neuron Receiving messages a when a neuron receives a signal two things occur i hyperpolarization the inside of the neuron becomes more negative ii depolarization the inside of the neuron becomes more positive b Absolute threshold when levels of stimulation within a cell reaches 55mv action potential occurs i When action potential occurs the neuron is stimulated Action Potential a Action potential is a brief shift in a neuron s charge that travels along the axon b Absolute refractory period after an action potential has occurred the sodium channels close and in this short period the cell is unable to fire more action potentials The Myelin Sheath a Made up of Schwann Cells that line the axon b The myelin affects the speed in which a neuron sends its signal it increases surface area thus making signals travel faster c Demyelination damage to the myelin sheath results in distorted and lost signals throughout the body i Example Multiple Sclerosis MS
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