‘L’ are specialised cells present in the human body that transmit nerve impulses. They are the longest cells in the body. Each ‘L’ has a long branch ‘M’ and a short branch ‘N’. Between two ‘L’ cells, a small gap ‘O’ is present through which nerve impulse is transmitted using a chemical substance ‘P’.

i. Identify ‘L’.
ii. Name ‘M’ and ‘N’.
iii. What is the gap ‘O’ called?
iv. Name the chemical substance ‘P’.
 
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