Before we can begin to understand the process that occurs when we touch the hot kettle we have to look at all the components involved. The human body is made up of the central nervous system (CNS) which consists of the brain and spinal cord. The brain communicates with the rest of the body through the spinal cord. From there messages flow through the peripheral nervous system (PNS), which is all parts of the nervous system outside the brain and spinal cord. The cells of the nervous system are called neurons, which is what carries the messages from the senses to the brain where it gets processed. A neuron is made up of three parts. Dendrites receive information from another cell and transmit the message to the cell body, the cell body or soma, and then the axon which conducts messages away from the cell body (Coon & Mitterer, 2008).
With the basic layout of the human network laid out, we can look at the process that goes on when we touch the hot kettle. When the hot kettle touches your arm or hand, a couple of different messages are sent from the point of origin to the brain and then back down again. One of those messages probably tells the brain “that’s hot and hot hurts” and the other is “pain is bad, pull arm away”.
When we touch the kettle a message travels from the dendrites to the soma down the axon to the next neuron. In order to actually get moving, electrically charged ions (found inside each neuron) send about minus 50 millivolts to the neuron which then reaches is threshold (point of firing) in order to send an action potential, or nerve impulse down axon. Myelin which is a fatty layer coats the axons of some neurons and contains small gaps which allow nerve impulses to move faster by leaping from gap to gap – a process called salutatory conduction. The gap in which messages pass is called synapse, and when an action potential reaches the tips of the axon terminals, chemicals which alter activities in neurons, or neurotransmitters...