visceral pain

Examples of visceral pain in the following topics:

• Localization of Pain

  • Localization of pain is determined by whether the pain is superficial somatic, visceral, or deep somatic.
  • Nociceptive pain may also be divided into visceral, deep somatic, and superficial somatic pain.
  • Visceral structures are highly sensitive to stretch, ischemia, and inflammation, but relatively insensitive to other stimuli that normally evoke pain in other structures, such as burning and cutting.
  • Visceral pain is diffuse, difficult to locate, and often referred to a distant, usually superficial, structure.
  • Referred pain (also reflective pain) is pain perceived at a location other than the site of the painful stimulus.

• Pain Sensation

  • Pain comes in two phases.
  • The pain associated with the Aδ fibers can be associated to an initial extremely sharp pain.
  • Nociceptive pain can be divided into visceral, deep somatic and superficial somatic pain.
  • Visceral structures are highly sensitive to stretch, ischemia, and inflammation, but relatively insensitive to other stimuli that normally evoke pain in other structures, such as burning and cutting.
  • Visceral pain is diffuse, difficult to locate, and often referred to a distant, usually superficial, structure.

• Autonomic Reflexes

  • In these cases, the body will interpret the afferent pain stimulus as somatic.
  • General visceral afferent sensations are mostly unconscious, visceral motor reflex sensations from hollow organs and glands that are transmitted to the CNS (see the following illustration for a depiction of a typical nerve fiber, including general visceral afferent fibers).
  • While the unconscious reflex arcs are normally undetectable, in certain instances they may send pain sensations to the CNS, masked as referred pain.
  • This pain is usually non-localized.
  • The pain is usually referred to dermatomes that are at the same spinal nerve level as the visceral afferent synapse.

• Vagus (X) Nerve

  • The vagus nerve (cranial nerve X) is responsible for parasympathetic output to the heart and visceral organs.
  • The solitary nucleus: Receives afferent taste information and primary afferents from visceral organs.
  • The spinal trigeminal nucleus: Receives information about deep/crude touch, pain, and temperature of the outer ear, the dura of the posterior cranial fossa, and the mucosa of the larynx.
  • This occurs commonly in cases of viral gastroenteritis , acute cholecystitis, or in response to stimuli such as the Valsalva maneuver or pain.

• Intercostal Nerves

  • Unlike the nerves from the autonomic nervous system that innervate the visceral pleura of the thoracic cavity, the intercostal nerves arise from the somatic nervous system.
  • This explains why damage to the internal wall of the thoracic cavity can be felt as a sharp pain localized in the injured region.
  • Damage to the visceral pleura is experienced as an unlocalized ache.

• Sensory Modalities

  • Nociception (physiological pain) signals nerve or other tissue damage.
  • The three types of pain receptors are cutaneous (skin), somatic (joints and bones), and visceral (body organs).
  • It was previously believed that pain was simply the overloading of pressure receptors, but research in the first half of the 20th century showed that pain is a distinct phenomenon that intertwines with all of the other senses, including touch.

• Pons

  • The alar plate produces sensory neuroblasts, which will give rise to the solitary nucleus and its special visceral afferent column, the cochlear and vestibular nuclei (which form the special somatic afferent fibers of the vestibulocochlear nerve), the spinal and principal trigeminal nerve nuclei (which form the general somatic afferent column of the trigeminal nerve), and the pontine nuclei, which is involved in motor activity.
  • Basal plate neuroblasts give rise to the abducens nucleus (forms the general somatic efferent fibers), the facial and motor trigeminal nuclei (form the special visceral efferent column), and the superior salivatory nucleus, which forms the general visceral efferent fibers of the facial nerve.
  • The functions of the four nerves of the pons include sensory roles in hearing, equilibrium, taste, and facial sensations such as touch and pain.

• Glossopharyngeal (IX) Nerve

  • It receives visceral sensory fibers from the carotid bodies, carotid sinus.
  • Visceral motor (general visceral efferent): Provides parasympathetic innervation of the parotid gland.
  • Visceral sensory (general visceral afferent): Carries visceral sensory information from the carotid sinus and body.

• Branches of Spinal Nerves

  • The dorsal ramus: Contains nerves that serve the dorsal portions of the trunk carrying visceral motor, somatic motor, and sensory information to and from the skin and muscles of the back.
  • The ventral ramus: Contains nerves that serve the remaining ventral parts of the trunk and the upper and lower limbs carrying visceral motor, somatic motor, and sensory information to and from the ventrolateral body surface, structures in the body wall, and the limbs.
  • The rami communicantes: Contain autonomic nerves that carry visceral motor and sensory information to and from the visceral organs.

• Endometriosis

  • Some women have little or no pain despite having extensive endometriosis with scarring, while others may have severe pain even though they have only a few small areas of endometriosis.
  • dysmenorrhea – painful, sometimes disabling cramps during menses, which may get worse over time (progressive pain), also lower back pain linked to the pelvis
  • chronic pelvic pain – typically accompanied by lower back pain and abdominal pain
  • In addition to pain during menstruation, the pain of endometriosis can occur at any time of the menstrual cycle.
  • There can be pain with ovulation, pain associated with adhesions, pain caused by inflammation in the pelvic cavity, pain during bowel movements and urination, during general bodily movement like exercise, pain from standing or walking, and pain with intercourse.