BIOL 260 Study Guide - Midterm Guide: Cerebrospinal Fluid, Extensor Digitorum Longus Muscle, Excitatory Synapse
21 Sep 2016
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Document Summary
Need bulky muscles with strong attachments to do plantar flexion. Muscles that preform dorsiflexion at the ankle are relatively slender. Extensor digitorum longus- on the anterior side of the leg. Tibialis anterior- on the anterior side of the tibia. Central nervous system: brain and spinal cord. Peripheral nervous system: everything else (sensory division and motor division, sensory division. Visceral sensory division- controls all other muscles. Neurons describe signal strength through ap frequency large signal= large graded potential at dendrites the number of action potentials per second tells you about the strength: the faster they occur the stronger they are. Glial cells create fatty myelin sheath on some axons. Schwann cells in pns and oligodendrocytes in cns create myelin. Myelin is the insulator that allows action potentials to travel very quickly. However, the depolarization only happens at nodes in between myelin sheaths, it then travels through the myelin to the next node- this is how it goes so fast.
