Nervous system Impulses
This article is intended for the massage therapist that is reviewing or the student that is preparing to take the national exam.
Nerve impulses can also be known as action potentials they are self-propagating waves of electrical disturbances that travel along the surface of a neuron’s plasma membrane. If you could slow down time and magnify the action it would look the a lightening bolt that is traveling down a wire or telephone pole along your street. If it encounters myelin covered sections of membrane it simple jumps around the myelin.
The beginning of the dendrites of sensory neurons where impulse conduction normally starts and often located at a distance from the spinal cord are called receptors. The group of nerve-cell bodies located in the PNS neat the spinal cord are called ganglion. But the microscopic space separating the axons and dendrites of different neurons are chemical signals which are sent across the gap (the gap being presynaptic and post synaptic neurons) is called a synapse. There are three structures to the synapse the synaptic knob, synaptic cleft, and finally the plasma membrane. The tiny bulge at the end of the terminal branch of the pre-axon is called the synaptic knob. Each synaptic knob contains many small sacs or vesicles that contain a very small quantity of a chemical compound called a neurotransmitter. The synaptic cleft is a narrow space that receives neurotransmitter molecules, and the plasma membrane is part of the post synaptic neuron.
Reflex is he response to an impulse conduction over a reflex arc, unlearned and involuntary response to something in the environment. Neurotransmitters known there are about 30 different ones known, chemicals by which neuron’s communicate. What is also known is that there are 12 pairs of cranial nerves and 31 pairs of spinal nerves. The cranial nerves branch out from the head and the spinal nerves branch out in pairs along the length of the spinal column.
