NERVOUS TISSUE
Nervous tissue is also an excitable type of tissue that receives as well as transmits messages nervous tissue is composed of only neurons
Neuron::
the structural and functional unit of the nervous system is the nerve cell or neuron the neuron is made up of the nerve cell body and its processes the dendrites and axons the nerve cell body consists of a large nucleus nissels grannules and neurofibrils present in the neuroplasm mitochondria and other cell organelles are also present in the nerve cell body the dendrites are receptive fibres which receive the impulses and transmit them to the nerve cell body whereas the axons carry the impulses away from the nerve cell body the nerve cell body may be of different types as follows
1. apolar ; i.e neither axon nor dendrite are attached with nerve cell .
2. unipolar ;i.e having only axon the apolar and unipolar type of cell bodies are found only in foetal life
3.Bipolar i.e having one axon and one dendrite such type of nerve cells are found in retina of the eye and vestibular ganglia
4.pseudounipolar i.e having two processes but both originating from one point these are found in all spinal ganglia and ganglia of the eighth cranial nerve
5. multipolar i.e having more than two processes such types of neurons are found in the cerebral cortex nuclei of trigeminal nerve and motar neurons of the spinal cord
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