Chapter 14: Somatosensory Function, Pain, Headache, and Temperature Regulation Flashcards
Somatosensory Component of the Nervous System - Function
provides an awareness of body sensations such as touch, temperature limb position and pain
the sensory receptors consist of discrete nerve endings in the skin and other body tissues
Four major modalities of sensory experience
- discriminative touch
- temperature sensation
- body position
- nociperception
Discriminative pathway from spinal cord to thalamic level of sensation
- crosses at the base of the medulla and the anterolateral pathway
- relays information to the brain for perception, arousal, and motor control
Anterolateral pathway from the spinal cord to thalamic level of sensation
- consists of bilateral multisynaptic slow-conducting tracts
- provide for transmission of sensory information that does require discrete localization of the signal source or fine discrimination of intensity
Pain Transmission
- transmission to the somatosensory of cortex
- limbic system
- brain stem centers
Pain Theory - Specificity Theory
pain as a separate sensory modality evoked by the activity of specific receptors that transmit information to pain centers in the forebrain
Pain Theory - Pattern Theory
- pain receptors share endings or pathways with other sensory modalities
- different patterns of activity of the same neurons can be used to signal painful and non painful stimuli
Pain Theory - Gate Control Theory
the presence of neural gating mechanisms at the segmental spinal cord level accounts for interactions between pain and other sensory modalities
Pain Theory - Neuromatrix
the brain contains a widely distributed neural network, called the body-self neuromatric, that contains somatosensory, limbic and thalamocortical individual neural patterns
Pain Threshold
the point at which a stimulus is perceived as painful
Pain Tolerance
the maximum intensity or duration of pain that a person is willing to endure before the person wants something done about the pain
Acute Pain
self-limiting pain that lasts less than 6 months
Chronic Pain
- persistent pain that lasts longer than 6 months
- lacks the autonomic and somatic responses associated with acute pain
- is accompanied by debilitating responses
Assessments of Pain
nature, severity, location, radiation
Allodynia
pain from noninjurious stimuli to the skin
Hyperalgesia
extreme sensitivity to pain
Analgesia
the absence of pain from stimuli that normally would be painful
Nociceptive Pain
Nociceptors (pain receptors) are activated in response to actual or impending tissue injury
Neuropathic Pain
arises from direct injury to nerves
Cutaneous Pain
- sharp, burning pain
- origin in skin or subcutaneous tissues
Deep Somatic Pain
- more diffuse and throbbing
- origin in body structures
Visceral Pain
- diffuse and poorly defined
- results from stretching, distention, or ischemia of tissues
Referred Pain
originates at a visceral site but perceived as originating in part of the body wall that is innervated by neurons entering the same segment of the nervous system
Nonpharmacologic Interventions for Pain
- cognitive behavioral: relaxation, distraction, imagery, biofeedback
- physical agents: heat and cold
- stimulus-induced analgesia
- acupuncture and acupressure
