The Sensation & Physiology of Pain

If you've ever wondered why and how we feel pain, here it is. Pain provides us with information about tissue-damaging stimuli. Because of our reactions to pain we are able to avoid further pain.

The receptors for pain are called nociceptors which are free nerve endings. These nociceptors are found in almost every tissue of the body so that we may avoid harm. These receptors respond to any stimulus along as it may cause tissue damage. This is why when we touch something hot we immediately jerk our hand away. Touch, pressure, heat and cold are among the things that can cause pain along with excessive muscle spasms and contraction, inadequate blood flow to an organ, or the presence of some chemicals. When a tissue becomes irritated it releases certain chemicals like taglandins and kinins. These chemicals help to stimulate the nociceptors to prevent further pain.

Pain can divided into two different types. Somatic and visceral. When somatic pain arises from the receptors in the skin it can be called superficial somatic pain. If the stimulation of receptors are located in the skeletal muscles, tendons, and joints it is called deep somatic pain. Visceral occurs when stimulation of receptors is in the viscera, internal organs.

Visceral pain doesn't cause the same type of pain that somatic pain does. Sometimes the pain of the internal organs is very light and sometimes there isn't any while somatic pain is usually always felt. In most instances of visceral pain the pain is most commonly felt under the skin that is on top of that organ. Sometimes the pain might be felt in a part of the skin that isn't directly near the injured organ and this rare instance is called referred pain. This is caused because the organs are served by dendrites, or nerve fibers, which are connected to a part of the spinal cord.

To deal with pain there is anesthesia. Anesthesia is administered during certain surgical procedures. It helps to block the sensation of pain in patients while still keeping the organs functioning. Two different types of anesthesia are general anesthesia and spinal anesthesia. General anesthesia gets rid of all sensations and also induces unconsciousness and in some cases, muscle relaxation. Eating is prohibited before being given general anesthesia because the anesthesia can induce vomiting during a procedure. Spinal anesthesia is an injection of a drug into the spine. This is typically used for surgery below the diaphragm. Some procedures include hernia repairs, operations on the hips, prostate gland, bladder, pelvis, and rectum.