59 A pain that radiates along the left shoulder and medial s

59. A pain that radiates along the left shoulder and medial side of the arm may not indicate a pain specifically in that area. This may indicate a heart attack, which causes pain, and the phenomenon is called pain A) somatic; visceral B) somatic, referred C) visceral; referred D) visceral, somatic E) referred, visceral

Solution

visceral ; referred

Visceral pain is pain that results from the activation of nociceptors of the thoracic, pelvic, or abdominal viscera (organs). Visceral structures are highly sensitive to distension (stretch), ischemia and inflammation, but relatively insensitive to other stimuli that normally evoke pain such as cutting or burning. Visceral pain is diffuse, difficult to localize and often referred to a distant, usually superficial, structure. It may be accompanied by symptoms such as nausea, vomiting, changes in vital signs as well as emotional manifestations. The pain may be described as sickening, deep, squeezing, and dull

.Referred pain is pain perceived at a location other than the site of the painful stimulus/ origin.It’s the result of a network of interconnecting sensory nerves. This network supplies many different tissues. When there is an injury at one place in the network, this pain can be interpreted in the brain to radiate nerves. And can give pain elsewhere in the related areas of the network.

The cardiac general visceral sensory pain fibers follow the sympathetics back to the spinal cord and have their cell bodies located in thoracic dorsal root ganglia 1-4(5). As a general rule, in the thorax and abdomen, general visceral afferent (GVA) pain fibers follow sympathetic fibers back to the same spinal cord segments that gave rise to the preganglionic sympathetic fibers. The central nervous system (CNS) perceives pain from the heart as coming from the somatic portion of the body supplied by the thoracic spinal cord segments 1-4(5). Classically the pain associated with a myocardial infarction is located in the mid or left side of the chest where the heart is actually located. The pain can radiate to the left side of the jaw and into the left arm. Myocardial infarction can be seen as referred pain and this usually occurs in people with diabetes or older age. Also, the dermatomes of this region of the body wall and upper limb have their neuronal cell bodies in the same dorsal root ganglia (T1-5) and synapse in the same second order neurons in the spinal cord segments (T1-5) as the general visceral sensory fibers from the heart. The CNS does not clearly discern whether the pain is coming from the body wall or from the viscera, but it perceives the pain as coming from somewhere on the body wall, i.e. substernal pain, left arm/hand pain, jaw pain.

further explanation

If you woke up with a pain in your shoulder, you\'d probably think something was wrong with your shoulder, right? Maybe you slept on it the wrong way, maybe you\'re a weekend warrior who threw the football a few too many times. In most cases, your hunch is probably right. Pain in the shoulder usually indicates an injury or disease that affects a structure in your shoulder, such as, say, your subacromial bursa or a rotator cuff tendon.

Sometimes the brain gets confused, making you think that one part of the body hurts, when in fact another part of the body, far removed from the pain, is the real source of trouble. This curious (and clinically important) phenomenon is known as referred pain. For example, it\'s unlikely but possible that your shoulder pain is a sign of something insidious happening in your liver, gall bladder, stomach, spleen, lungs, or pericardial sac (the connective tissue bag containing the heart). Strange, isn\'t it? Conditions as diverse as liver abscesses, gallstones, gastric ulcers, splenic rupture, pneumonia, and pericarditis can all cause shoulder pain. How is that possible?

In a nutshell, referred pain happens when nerve fibers from regions of high sensory input (such as the skin) and nerve fibers from regions of normally low sensory input (such as the internal organs) happen to converge on the same levels of the spinal cord. The best known example is pain experienced during a heart attack. Nerves from damaged heart tissue convey pain signals to spinal cord levels T1-T4 on the left side, which happen to be the same levels that receive sensation from the left side of the chest and part of the left arm. The brain isn\'t used to receiving such strong signals from the heart, so it interprets them as pain in the chest and left arm.