PSYC-1105EL Lecture Notes - Lecture 4: Axon Terminal, Multiple Sclerosis, Neuroglia
12 Jan 2021
School
Department
Course
Professor
Document Summary
Allows for more ef cient signalling in nervous system. Sensory: carry input messages from the sense organs to the spinal cord and brain. Motor: transmit impulses from the brain and spinal cord to the muscles and organs. Interneurons: perform connective or associative functions in the nervous system. Axon - transmits signals away from soma to other neutrons or muscles/glands. If myelin deteriorates, cannot transmit signals effectively. Insulation layer covers axons in the brain and spinal cord. Thicker axons transmit neurons more rapidly than thinner ones. Multiple sclerosis occurs when immune system attacks the sheath. Terminal button - end of axon; secretes neurotransmitters. Microscopic gap (synaptic cleft) between terminal button of one neutron and cell membrane of another. Resting potential - stable (negative) charge (-70 millivolts) The action potential - brief shift in neuron"s electrical charge. All-or-none law - either an action potential occurs or it doesn"t. One neuron, signals from thousands of other neurons.
