Action potential In spinal motor neuron generates from -

Ans. is 'd' i.e.. Initial segment Action potential In Sensory neuron generates from- Node of Ranvier In spinal motor neuron- Initial segment >Axon hillock o The neuron is the functional unit (the basic unit of nervous tissue). It is specialized for the function of reception, integration and transmission of information in the body. The basic structure of the neuron is best studied in a spinal motor neuron. This cell has a ''cell body (soma)' with 5-7 small processes called 'dendrites'. There is a long process called 'axon' that originate from "axon hillock (A thickened area of cell body from %vhich axon originates)". The first portion of the axon is called "initial segment". In a motor neuron, the axon hillock and the initial segment of axon have the lowest threshold for excitation. This is because they have a much higher density of voltage-gated sodium channels. o Functionally speaking, the neuron can be divided into four zones : - Dendrites and Soma (cell body) - Receptor zone Axon hillock of body & initial segment of axon - Generator area (Nerve impulse is generated). Axon (main length) - Transmitter zone (Transmits nerve impulse). The nerve terminals (Terminal knobs or buttons) : - Release zone (release neurotransmitters).