FEELING

Some parts of the body are more sensitive to feelings than others. The lips, tongue, hands and feet are among the most sensitive. That is because these parts contain many nerve endings. Touch something with your finger, and you can feel it almost  immediately; the nerve endings in your finger have sent an electrical signal to your brain via the spinal cord. Your brain distinguishes between nerve messages indicating, for example, tickle, Itch, cold, heat, touch, pressure or pain, and registers the intensity of the signals. A strong signal, for example if you touch a hot saucepan, you will pass straight back from the spinal cord to your arm muscle – so that you pull your hand back as a reflex action at about the same time as the message reaches your brain.

The sensory nerves have specialized nerve endings to pick up different sensations, such as heat or cold. They can also  have axons ( eg those coming from the nerve endings for pressure) than  along thin ones; some axons can even be over a more long, such as those leading from the base of the spinal cord to the big toe.

·        Each person has a different pain threshold. The bath temperature that seems fine to one person may be painfully hot to another.

·        One pain can suppress another. If you stub your toe, biting your lip or thumping your fist  on a table may help reduce the pain.

·        Pain can sometimes be felt in a different place from its actual source. For example, a pain may appear to your brain to be coming from your neck or shoulders, when in fact it comes from the diaphragm. This results from a ‘crossed line’ between neighbouring nerves.

·        People who have lost a limb sometimes think they still feel pain in it, because the brain is still getting signals from the stump.