Visceral Pain Flashcards
What are the two critical phenomena in pain science besides nociceptive processing in the skin?
The two critical phenomena are visceral pain and referred pain. These types of pain involve internal organs and are distinct from pain originating in the skin.
What causes visceral pain?
Visceral pain is caused by mechanical or chemical stimulation of internal organs. Examples include gallstones moving through the biliary tract, kidney stones, and inflammation of the appendix.
How is visceral pain typically characterised?
Visceral pain is often diffuse, with a burning sensation. It may also be accompanied by vegetative responses, such as sweating, suggesting that C fibers are mainly responsible for visceral pain.
What is referred pain in the context of visceral pain?
Referred pain is the sensation of pain in a body region distant from the actual source of visceral pain. For example, during a heart attack, pain may be felt in the little finger, elbow, shoulder, or back.
What are some examples of referred pain locations for specific internal organs?
Kidney pain can be referred to the groin, biliary tract pain can manifest in the middle of the back, and pain from the heart during a myocardial infarction can be felt in areas such as the arm or back.
What is the convergence-projection theory of referred pain?
The convergence-projection theory postulates that dorsal horn neurons receive nociceptive input from both an internal organ and a localized skin area (dermatome). These inputs converge on the same neuron, leading to the experience of referred pain.
How do dermatomes relate to referred pain?
Dermatomes are areas of skin that develop in tandem with internal organs during fetal life. The convergence of nociceptive input from these dermatomes and internal organs on the same neuron in the dorsal horn results in referred pain.
