Types of Pain
2 Types: Fast and Slow
Fast Pain : Perception of fast pain is rapid at 0.1 seconds after the stimulus because the impulse propagates along medium-diameter, myelinated A fibres . This type of pain is also known as acute, sharp, pricking pain and is not felt in deeper tissues of the body. An example is a needle puncture or knife wound. Fast pain is localized very precisely to the stimulated area. Slow Pain : Perception begins a second or more after the stimulus then generally increases in intensity over several seconds/minutes. Impulses propagate along small-diameter, unmyelinated C fibres . This type of pain is chronic, burning, aching, throbbing pain and can occur in the skin or deeper tissues or internal organs. An example is a toothache. Slow is also well localized but more diffuse.
Superficial Somatic Pain : pain from stimulation of receptors in the skin.
Deep Somatic Pain : pain from stimulation of receptors in skeletal muscles, joints, tendons, and fascia.
Visceral Pain : pain from stimulation of nociceptors in visceral organs.
Referred Pain : Visceral pain that is felt in or deep to the skin over the organ or far from the organ. The visceral organ involved and the area where the pain is felt are served by the same spinal cord segment. Example: sensory fibres from the heart, the skin over the heart, and the skin along the medial left arm enter spinal cord segments T1-T5
4) Proprioceptive Sensations
These sensations allow us to know where our head and limbs are located and how they are moving even if we are not looking at them such as when a horse moves without using thier eyes. These sensations arise from receptors called Proprioceptors embedded in muscles (especially postural) and tendons (degree of muscle contraction, tension on the tendons, position of joints).
Proprioceptors adapt slowly and only slightly so the brain continually receives impulses related to position of different body parts and makes adjustments to ensure coordination. Weight Discrimination : proprioceptors give us the ability to assess the weight of an object and help to determine the muscular effort necessary to perform a task. Example: pick up an object and realize how heavy it is – brain makes the necessary corrections in muscular contraction to accomplish the task (if possible).
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