BIOL 1080 Lecture Notes - Lecture 10: Multiple Sclerosis, Oligodendrocyte, Myelin
Document Summary
Not all info needs to go to the brain! Allows rapid reflex w/o delay through spinal cord. Ex: pain! (right foot steps on tack: reflex --> right leg pulls back while left leg extends for balance, brain recognizes pain, remembers it so that you don"t step on it next time :p. 5 major cell types in the ccn: neurons, unidirectional information flow. Unmyelinated = 0. 2~5m/s vs myelinated = 6~120 m/s. Speed depends on neuron! (pain fibers aren"t the fastest tho :p but they"re fasts enough!) One type of neurotransmitter released per presynaptic neuron! Target cells can respond to many types tho: either excitatory or inhibitory. Based on overall summation of all the inputs! Literally takes in and sums up thousands of inputs! Net effect ==> action potential or not (since it"s an all-or-none principle!) Converge = multiple neurons connect to one (#2~5 = glial cells: oligodendrocytes (cns) & schwann cells (pns, make myelin!! Astrocytes: more abundant than neurons, very important!!
