Nervous tissue - a highly specialized tissue composed of neurons (neurocyte) and glia (support cells).It develops from the neural tube and 2 ganglion plates and forms the central and peripheral nervous system.Nerve cells perceive irritation, then they go into a state of excitement, generate and transmit pulses.The cells are glia fill the gaps between the neurocytes and support them, that is, performs the support, protective, secretory function and is involved in the metabolism between neurons and blood vessels.
Neuron consists of a star-shaped body, polygonal or oval shape and off-shoots of it.Typically, neurocytes have one or two long, thin branches (axons) and a few thick and short (dendrites).Dendrites are highly branched and are located close to the
cell body.They perceive and convey the excitement of neurocytes.Axon, with branches off of it, transmits the excitement from one neuron to another, or the impetus for it is directed to the cells of other tissues.Long processes form the nerve fibers.
Some axons are covered with clusters of fat-education, which is called the myelin sheath.This multilayer coating increases the diameter of the fiber and gives it a white color.From myelinated white matter consists of fibers of the brain and spinal cord.Nerve fibers without such coatings are gray.
main functions of the nervous tissue is the perception, processing and transmission of information.Neurons transmit impulse to each other at the contact of two neurocyte - synapses, via neurotransmitters.The sending neuron releases a neurotransmitter into the synapse, and taking catches it and turns into an electrical impulse.The nerve endings respond to different stimuli: mechanical, chemical, electrical and thermal.But they all have to be certain forces and act long enough.
distinctive property of nerve tissue - new neurons throughout the life of the body are formed.