A.Explain how a light touch stimulates a nerve impulse?

Question

B.How does the impulse travel to the brain?
C.Where in the brain is the impulse received?

Answer 1

When you are touched (enough for you to feel, anyway), the nerves in that area of your body are compressed. These nerves respond to compression. Voltage gated ion channels, located on the axon, open up. Sodium ions (positively charged) rush in through the suddenly open channels, attracted by the negative charge present inside the axon itself, leading to depolarization of the area immediately around the channel. Depolarization of one section of the axon stimulates the opening of other voltage gated ion channels, and as a result there is rapid depolarization across the axon.

Once this depolarization reaches the dendrite (main body of the nerve cell), a signal is released into a synapse (the space between one nerve cell and another). The second nerve cell recieves this signal, and passes it on to the next nerve, and then the next, and so on until the signal reaches the brain.

I don't know which part of the brain recieves the signal off the top of my head (maybe the hypothalamus?). But once the signal is recieved, the brain translates it into a feeling for you, in your light touch example perhaps a tickle. The brain can send a signal back down a different set of nerve cells, stimulating a response (like trying to get away from whatever is tickling you). Nerves only go one way, either from somewhere to the brain, or from the brain to somewhere.

Answer 2

do your homework yourself