Question

when we touch a hot object we move r hand back . but whe this impulse is carried through neurons to the spinsl cord or brain how do they convey this to the brain because niether they can speak nor thier can be different chemichals fr different types of impulses and the body also reacts itself , so how does it know wether to move left or right

Answer 1

Right, when we touch a hot object we move our hand back....

There are two types of nerves
1) Sensory nerve
2) motor nerve

sensory nerve make the sensation of object when we touch....it only determines whether the object is hot or cool big or small smooth or hard etc......

it sends the massage to the Brain. through Axons.

(Axons and dendrites are the part of neurons which send and receives the massage respectively....)

As Brain get massages send by sensory nerve, it gives the command to the motor nerve.
And finally motor nerve perform the operation given by brain...and massages transfer through dendrites.

this happens within a second....

Now, According to your question....when hot object comes in the contact of our body..... suddenly sensory nerve send the massage to spinal cord (brain) and then motor nerve pulls the hand back.....

I hope you Understood .....
i u have any queries​....ask in the comment box.
Thanks