Question

The nerve cells in a chef’s hand sense heat from a pan. The nerve cells send signals to the chef’s brain. The brain sends signals to the hand to release and drop the pan.

Answer 1

We sense temperature in our environment through specialised nerve cells that project into the outer layers of the skin. These nerve cells are activated by high temperatures and capsaicin, the substance that makes chilli peppers hot. In response to a stimulus like heat or capsaicin, proteins on the surface of nerve cells called ion channels open up a channel that lets charged ions flow into the cell, setting off a nerve impulse. The impulse travels along sensory neurones to the spinal cord and then up to the brain, where it is interpreted as heat.