Transmission of impulses define with diagram.Handwritten plz
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Transmission of Nerve Impulses
The transmission of a nerve impulse along a neuron from one end to the other occurs as a result of electrical changes across the membrane of the neuron. The membrane of an unstimulated neuron is polarized—that is, there is a difference in electrical charge between the outside and inside of the membrane. The inside is negative with respect to the outside.
Polarization is established by maintaining an excess of sodium ions (Na +) on the outside and an excess of potassium ions (K +) on the inside. A certain amount of Na + and K + is always leaking across the membrane through leakage channels, but Na +/K + pumps in the membrane actively restore the ions to the appropriate side.
The main contribution to the resting membrane potential (a polarized nerve) is the difference in permeability of the resting membrane to potassium ions versus sodium ions. The resting membrane is much more permeable to potassium ions than to sodium ions resulting in slightly more net potassium ion diffusion (from the inside of the neuron to the outside) than sodium ion diffusion (from the outside of the neuron to the inside) causing the slight difference in polarity right along the membrane of the axon.
Other ions, such as large, negatively charged proteins and nucleic acids, reside within the cell. It is these large, negatively charged ions that contribute to the overall negative charge on the inside of the cell membrane as compared to the outside.