Week 4 Flashcards
somatic vs. visceral pain
somatic: from skin or bine muscle, conducted by sensory fibers
visceral: from organs, conducted by sympathetic fibers, acute or chronic
sensory dimensions
location, intensity, pattern, quality
pain threshold
the point at which stimulus is perceived as painful
pain tolerance
the maximum intensity or duration of pain that a person is willing to endure before doing something about it
Autonomic responses
to protect the individual (eg. moving your hand from a hot stove)
Behavioural responses
Learned behaviours as a method to coping with the pain (eg. rubbing a sore leg)
Hyperalgesia
an increased sensitivity to pain, which may be the result of damage to nociceptors or peripheral nerves (eg. shingles)
neural mechanisms by which pain is perceived (nociception)
transduction, transmission, perception, modulation
transduction
The conversion of a mechanical, thermal or chemical stimulus into a neuronal action potential. occurs at free nerve endings
transmission
The movement of pain impulses from the site of transduction to the brain
the 3 segments involved in nociception signal transmission
Segment 1: Transmission along nociceptor fibers (A & C) to the spinal cord
Segment 2: Dorsal Horn Processing ((includes the release of neurotransmitters (eg. substance P) which may either excite or inhibit the cell.)
Segment 3: Transmission to the thalamus and cortex (pain pathways)
perception
Occurs when pain is recognized, defined and responded to.
Conscious awareness of the pain.
Subjective interpretation
Modulation
Pathways that integrate nervous system impulses (from nociceptors, peripheral sensory axons, spinal interneurons etc.) (Involves the activation of descending pathways that exert inhibitory or excitatory effects on pain transmission that will either suppress or facilitate pain)
Gate control theory
Gates open: Pain impulses transmitted from periphery to brain
Gates closed: Reduces or modifies the passage of pain impulses
Increased Intracranial Pressure
Increase in fluid or additional mass causes increase in pressure in the brain. (Ischemia and eventual infarction and death of brain tissue)
Increased ICP is common in …
Brain hemorrhage, trauma, cerebral edema, infection, tumors, abnormal circulation of CSF
Early signs of increased ICP—if cause is not removed
Decreasing level of consciousness or decreased responsiveness (lethargy)
Severe headache
(From stretching of dura and walls of large blood vessels)
Vomiting
(Often projectile, not associated with food intake)
(Result of pressure stimulating the emetic center in the medulla)
Papilledema
(Caused by increased ICP and swelling of the optic disc)
if ICP is not relived it can cause
drop in BP
respiratory controls get destroyed
cheyne-strokes respirations
different types of herniation
transtentorial- Cerebral hemispheres, diencephalon, midbrain are displaced downward
uncal- Uncus of the temporal lobe is displaced downward.
infratentorial- Cerebellar tonsils are pushed downward through the foramen magnum.
types of seizures
general- Widespread onset with abnormal discharges synchronized throughout all or most of the brain from onset (absence, blank stare or motionless) (myoclonic, brief)(tonic-clonic, MOST COMMON)
partial- Onset in a specific restricted area
status epilepticus
Recurring seizures in rapid succession, No break to regain consciousness, Can cause permanent neuronal damage,
May lead to respiratory failure and death
treatment for seizures
anticonvulsant drugs
what is autonomic dysreflexia
Massive sympathetic reflex response that cannot be controlled from the brain,
often initiated by infection, genital stimulation, or other stimuli (occurs with injury of cervical spine)
leads to:
-Increased blood pressure
-Vasoconstriction below the injury
-Vasodilation above the injury
-Bradycardia
complication of spinal cord injury
- Urinary tract infections
- Pneumonia
- Skin breakdown
- Spasm and pain ( resulting in contractions)
- Depression
- Sexual dysfunction and reproductive capacity
