Touch+and+Pain+P2+Sara+and+Anna

The sense of touch can be stimulated by various factors. These factors include: light touch, heavy touch, vibration, pressure, heat, and pain. Pain is a specific and particularly intense type of touch sensation that has been proven to be linked to emotion and survival. The sense of pain, just like the sense of touch, can be stimulated by specific experiences. A person’s sense of pain will activate in response to feelings of tearing, puncturing, burning, and sharp pressure. The senses of touch and pain both originate from the contact from an outside force with the skin. The skin is made up of three layers. The middle layer, called the dermis, is the most dense because it is home to all of the nerve endings that lead into the body. If a human comes into contact with something that puts enough pressure on the outer layer of skin to active the nerves on the dermal layer, a person will experience the sense of touch. Once a nerve is activated in the dermis, the nerves will send a signal to activate nerve fibers that travel through the spinal cord and up into the brain stem. Once the nerve signals reach the brain, they are sent through the thalamus. After this, the cells are processed in the area of the cerebral cortex that is dedicated to the specific body part that has been touched. The amount of space in the cortex that is dedicated to each body part depends on the density of nerve endings in that part of the body. When someone experiences pain, a similar signal is sent up to the brain that tells neurons that damage has occurred on the body and that the body must react. All vertebrates feel pain and some non-vertebrates may feel pain as well, for example the octopus. It is hard to test if animals feel pain because they cannot communicate their reactions to pain and touch, but most vertebrates will let out a cry when they experience pain. Each sense has a threshold, or the point at which a stimulus is of sufficient intensity to begin to produce an effect for that sense. For the sense of touch the threshold is the force exerted by dropping the wing of a bee onto your cheek from a distance of 1 centimeter. The main function of pain is to warn us about danger, therefore you will avoid dangerous situations because the brain is aware that that situation causes pain. This happens because of sensitization which is the process of becoming susceptible to a given stimulus that previously had no effect or significance on your brain. Because of sensitization the brain knows that when you feel pain you have to stop doing the action that is causing the pain.

FUN FACTS:
 * Women feel more pain then men because they have more nerve receptors, for example women have 34 nerve fibers per square cm of facial hair while men only have 17.
 * Chronic pain shrinks the brain, people with chronic backaches have brains as much as 11% smaller than those who do not.
 * You have more pain nerve endings than any other type.
 * The least sensitive part of your body is the middle of your back and the most sensitive areas are your face, hands, lips, neck, tongue, fingertips, and feet.
 * <span style="background-color: transparent; color: #000000; font-family: Arial; font-size: 15px; text-decoration: none; vertical-align: baseline;">There are about 100 touch receptors in each fingertip.
 * <span style="background-color: transparent; color: #000000; font-family: Arial; font-size: 15px; text-decoration: none; vertical-align: baseline;"><span style="background-color: transparent; color: #000000; font-family: Arial; font-size: 15px; text-decoration: none; vertical-align: baseline;">Rattlesnakes use their skin to feel the body heat of other animals.
 * <span style="background-color: transparent; color: #000000; font-family: Arial; font-size: 15px; text-decoration: none; vertical-align: baseline;"><span style="background-color: transparent; color: #000000; font-family: Arial; font-size: 15px; text-decoration: none; vertical-align: baseline;">The skin is the largest organ in the body weighing about 6-10 lbs.