The Nervous System Essay example

770 Words Mar 17th, 2016 4 Pages
The human brain consists of about 100 billion nerve cells that receives and send messages to other cells through chemical and electrical means (Skaggs, 2013). The main job of the nervous system is to receive data through sense organs, translates messages, process and respond to both internal and external stimuli (Saladin, 2012 p440). Nervous system uses chemical and electrical signal to communicate from neurons to another at high speed. More than 100 billion neurons found in the brain. Basic part of what make neurons are consist of dendrites which receives send messages, cell soma which is the cell body that process and translate code messages, and the axon where processed messages pass through to communicate to other nerve cells. The axon terminal also called pre-synaptic end of the nerve cell contain neurotransmitters and other molecule held in synaptic vesicle for transportation and receiving from a post-synaptic end called dendrites (Saladin, 2012). Axons are either myelinated or unmyelianated. With mylinated axon, nerve impulses conduct faster (3-5m/s) than unmylinated axon (0.5-2.0m/s) (Saladin, 2012). Transmission of message from one nerve cell to the other depends on the electrical potential charge difference of the cell membrane known to cause action potential to happen. Resting membrane of the cell resides to -70mV where no stimulus is trigger. At -55mV to +35 depolarization happens in the cell membrane where Na+ channels opens. At +35mV to -70mV re-polarization…

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