With the dark nights drawing in and the temperature dropping we all think ‘it’s that time of year again.’ At this time of year, I find myself wearing multiple layers and trying to stop my teeth from chattering and my body from shivering, the same as most people I imagine.
A part of the brain called the hypothalamus is responsible for regulating our body temperature. When we get too cold, the hypothalamus sends signals, called nerve impulses, to various parts of the body. If sent to the skin they cause goose bumps. Goose bumps arise from the contraction of tiny muscles in our skin causing our hairs to stand on end. This response causes air to become trapped at the surface of the skin, and this warms our body. This type of response however has developed from our ancestors who used to be a lot more hairy, and we don’t have enough hair for this response alone to warm us!
Nerve impulses are also sent to the muscles causing us to shiver. Muscles of the jaw called the periodontal and masseter muscles, receive nerve impulses causing them to contract. This then causes our teeth to chatter! One result of muscle contraction is heat, so this is why our body shivers and our teeth chatter! Next time your teeth start chattering, you can thank your hypothalamus for trying to keep you warm!
For those of you interested, this website has an interesting video on how music can cause goose bumps!