Class #10 Flashcards
What are the 4 somatosensory modalities?
- Tactile (mechanoreception)
- Thermal
(Thermoception) - Position
(proprioception) - Pain
(nociception)
Explain mechanoreception
The sensation of pressure/vibration. You will often feel the initial response, but will experience total adaptation over time. For example, feel your shirt going on, but then forget about it
Explain thermoception
The sensation of heat. Often you will experience an initial response, and then have partial adaptation. For example, the hot tub is really hot at first and then you will adapt
What is proprioception?
The send of limb/body movement in space without using vision
What is nociception?
The sensation of pain
Define pain
Unpleasant sensory and emotional sensation associated with actual and potential tissue damage
What are the 3 benefits of pain?
- Warns of impending injury
- Motivates seeking help
- Motivates to avoid future injury
Explain the 3 pathways that transmit somatosensory information
- A–> large myelinated fibers, fastest rate of conduction, convey cutaneous pressure, touch, cold/heat, and mechanical pain
- B–> Large, myelinated fibers, transmit information from cutaneous and subcutaneous mechanoreceptors
- C–> “slow pain”
-small, non-myelinated fibers
-Warm/hot, mechanical/chemical/
heat/cold induced pain
Explain the 3 levels of neurone involved in somatic sensation
- first order
- detect the sensation from sensory receptors to dorsal horn neurons - second-order
- occurs in the spinal cord, transmits the information to the thalamus
3, third order
-transmits information from the thalamus to the sensory cortex
How is the somatosensory component of the nervous system different than the specialized senses?
it provides an awareness of the body’s deep and superficial parts as opposed to awareness of the external world
What are the 3 types of sensory neurons present in the somatosensory system?
- General somatic afferent
- pain, touch, temperature - Special somatic afferent
- located in muscles, tendons and joints - General visceral afferent
- located on visceral structures that sense fullness and discomfort
What is a dermatome?
The region of the body wall that is supplied by a single pair of dorsal root ganglia
If your patient loses one dorsal root or root ganglion, will they completely lose sensation in this area? Why or why not?
Reduced but not total loss of sensory innervation of a dermatome, because neighbouring dermatomes overlap one another sufficiently
The _____________ system is considered the basic somatosensory system
tactile
What are free nerve endings responsible for?
They are found in the skin and the cornea, and they detect touch and pressure
What are Meissner corpuscles responsible for?
found in non-hairy parts of the skin like the fingertips, lips and other areas where the sense of touch is highly developed. They are able to adapt in a fraction of a second.
How are Merkel disks different from Meissner corpuscles?
Merkel disks transmit an initial strong signal that diminishes in strength but is SLOW in adapting. They allow for continuous determination of touch against the skin
When you feel a light hair brushing against your lips, what kind of tactile receptor is likely informing you of this?
Meissner corpuscles, because they are extremely sensitive to light touch and low frequency
What type of specialized receptor is specialized for detecting tissue vibration?
pacinian corpuscle immediately beneath the skin and deep in the fascial tissues
Explain the specificity theory
Considers pain to be a separate modality evoked by the activity of specific receptors (nociceptors) that transmit information to pain centres in the brain
How does the pattern theory explain pain?
Pain receptors share pathways and/or nerve endings with other sensory modalities. For example, light touch may not cause pain, but heavy touch of the same area may cause pain
Explain the gate control theory of pain
claims that there are neural gate mechanisms in the spinal cord that can block info from going to the brain by, for example, involving fibers that sense touch
What is the neuromatrix theory of pain?
a multifactoral theory of pain that claims that the brain a widely distributed neural network that contains genetic, cognitive and sensory influences. This theory helps explain phantom limb pain and chronic pain
Define pain threshold
The point at which a nociceptive stimulus is perceived as painful. This threshold is uniform from person to person
Define pain tolerance?
Maximum intensity or duration of pain a person is willing or able to endure. This is variable from person to person, depending on psychological, familial, cultural, and environmental factors
What is acute pain? Explain the early wave and the secondary wave.
Short-lasting pain that ceases when the cause is removed.
EARLY: hyper excites the neuron
SECONDARY: the longer lasting re-percussions of the acute injury, including the inflammatory reaction to the tissue injury
What are the 4 types of chronic pain?
- Highly variable
- not “usual” pain characteristics - Peripheral
- musculoskeletal, organ, vascular - Peripheral-central
- neuralgias, phantom limb pain - Central
- CNS disease or injury
What are the possible negative consequences of chronic pain?
- Psysiological
- loss of appetite, sleep disorders - Psychological
- depression - Familial
- Economic
What is the difference between cutaneous pain and deep somatic pain?
CUTANEOUS -arises from skin, cutaneous tissues -localized sharp, burning DEEP SOMATIC -from deep structures like muscles, tendons, joints, and blood vessels -difuse, radiating pain
What causes visceral pain?
activation of nociceptors of thoracic, pelvic or abdominal viscera.
- extremely sensitive to distension, ischemia and inflammation (diseases)
- Relatively insensitive to cutting/burning
How does visceral pain present in a patient?
- diffuse
- often referred
- deep, squeezing, sickening
- nausea, vomitting, emotional
What is referred pain? Why does this happen?
pain/injury originating in the viscera that is experienced as pain more near the body’s surface
- visceral and peripheral neurons converge
- structures develop nearby as embryo
- *LOOK THIS UP**
Define analgesia
Absence of pain
What is Hyperalgesia
increased sensitivity to pain
If someone has a decreased sensitivity to pain, what is this called?
hypoalgesia
What is hyperpathia?
unpleasant, prolonged response to pain that appears as an explosive overreaction to pain
Define hyperesthesia
Abnormal increase in sensitivity to sensation
What is Hypoesthesia?
Abnormal decrease in sensitivity to sensation
Define paresthesia
Abnormal touch sensation without external stimuli; tingling, pins and needles
What is Allodynia?
Pain produced by stimuli that does not normally cause pain
Ex: tapping on the shoulder causes pain
What causes neuropathic pain?
- pressure on the nerve
- physical/chemical injury to neuron
- infection/ischemia or inflammation of neuron
What is the difference between the causes of focal and global neuropathic pain
FOCAL
-trauma/disease of specific neuron
GLOBAL
-endocrine disease (diabetes), neurotoxic meds, chronic alcoholism
List 4 qualities explaining neuropathic pain
- unexplainable
- occurring without provocation
- widespread pain
- sensory deficits
- burning/stabbing pain
Neuropathic pain that occurs after shingles is called ___________
post-herpetic neuralgia
Severe, brief, repetitive attacks of lightening-like, throbbing pain along a spinal or cranial nerve are called ____________
Neuralgias
What can precipitate neuralgias?
stimulation of a cutaneous region supplied by nerve
Describe trigeminal neuralgia
the most common type of neuralgia, that causes facial tics and spasms. It is possible caused by trigeminal nerve damage
What 4 things trigger trigeminal neuralgia?
- light touch
- movements
- drafts
- eating
What virus causes shingles?
varicella-zoster virus
What triggers post-herpetic neuralgia?
- light touch
- cold wind
- clothing
What is Complex Regional Pain Syndrome (CRPS)?
a RARE, autonomic and vasomotor instability that causes an individual to be more sensitive about an injury than that injury warrants
How can I expect my patient with CRPS to present?
- pain that begins with one limb, then expands
- severe pain or hyperalgesia
- edema, blood flow changes
- abnormal sensorimotor activity
What is the difference between CRPS I and CRPS II?
CRPS I– occurs when there is no definable injury (allodynia)
CRPS II- hyperalgesia AFTER an injury
What can trigger a secondary headache?
- disturbed sleep
- over-exertion
How long does a migraine headache usually last?
1-2 days
If I have a migraine headache, how would I describe it?
- Unilateral, pulsating, throbbing pain
- made worse by physical activity
- nausea/vomiting
- light/sound sensitivity
- visual hallucinations (sparks, flashes)
Explain the “aura” that occasionally accompanies migraine headaches
- Pre-symptom to migraine
- develops over 5-20 mins, lasts up to one hour
- flickering lights, loss of vision
- pins/needles
- numbness
- speech disturbances
What is the criteria for a “chronic migraine”?
Experience a migraine headache 15+ days per month x 3 months
What is a retinal migraine?
a rare type of recurrent migraine headache that causes scintillations, scotomata, and blindness in one eye
*REVERSIBLE SYMPTOMS
Define a “transformed migraine”
similar to a tension or sinus headache that probably occurs d/t parasympathetic activation
List the symptoms that accompany childhood periodic syndrome migraines.
3 of the following:
- family history
- aura
- throbbing headache
- abdominal pain
- nausea/vomiting
- unilateral location
- relief with sleep
Migraines are most often associated with activation of which cranial nerve?
Trigeminal nerve
What hormone is though to be related to the development of migraine headaches?
Estrogen
Name 3 possible dietary triggers for migraine headaches
- MSG
- Cheese
- Chocolate
What part of the brain is thought to be associated with cluster headaches?
- Trigeminal nerve and ANS
- hypothalamus
Who are most likely to experience cluster headache?
- Men
- 30-70 years old
What is the most common area to experience a cluster headache?
ORBITAL, around or behind the eyes, can radiate to the temples, cheeks and gums
How might my patient with a cluster headache explain his pain?
- rapid onset lasting 15-180 mins
- severe, constant, unilateral
What secondary symptoms may my patient with a cluster headache exhibit?
- restlessness/agitation
- conjunctival redness/lacrimation
- nasal congestion/rhinorrhea
- facial sweating
- eyelid edema, ptosis
What type of headache is associated with oromandibular dysfunction?
Tension-type headache
Tension-type headaches are associated with….
- scalp/neck muscle tension
- oromandibular dysfunction
- stress, anxiety, depression
What 2 things cause tempomandibular joint pain?
- Imbalanced joint movement (poor bite, bruxism (grinding teeth), inflammation, trauma, degeneration)
- Pain (facial, head, neck, ear)
Do children respond to nociceptive stimuli as neonates?
YES. They have been proven to demonstrate pain memory as infants. They are reliable reporters of pain at a young age
What are the 3 most common types of pain in the older adult?
- musculoskeletal
- rheumatologic
- neurologic
Unrelieved pain in the older adult can lead to……
- gait disturbances
- muscle wasting
- impaired apetite
- sleep disturbances
- decreased cognition
- economic impact
What are Cannon’s 4 features of homeostasis?
LOOK THIS UP
- Mechanisms to maintain constancy
- Change from “steady-state” causes a response
- Response is multifactorial & cooperative, simultaneous or successive
- Organized self government
Controllable periods of stress that contribute to emotional and intellectual growth are known as _______________
Eustress
What is Allostasis? Why is this valuable?
Interactive physiologic changes in neuroendocrine, autonomic and immune systems in response to real or perceived challenges/threats to homeostasis
*Increases chance of survival
What is the difference between an endogenous stressor and an exogenous stressor?
ENDO: within the body
EXO: outside the body
A person’s response to stress is dependent upon….
- Properties of the stressor
- Condition of the person being stressed
INTERNAL (genetic, age, gender)
EXTERNAL (environment, exposure, experience, diet, social support)
Define General Adaptation Syndrome
-general systemic reaction in response to a stressor resulting in physical manifestations coordinated and dependent on each other
Explain the 3 stages of General Adaptation Syndrome
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ALARM STAGE -sns and hpa axis stimulation -catecholamines and cortisol released RESISTANCE STAGE -body responds and adapts -cortisol levels drop EXHAUSTION STAGE -resources are depleted *Damage to systems if prolonged
Which neurohormone involved in the stress response is responsible for potent vasoconstriction?
Angiotensin II
What is the role of Aldosterone in the stress response?
increase energy and glucose stores
What is cortisol responsible for?
- potentiates epinephrine and glucagon
- decreases non-essential energy-using activities, like metabolic rate, reproduction, osteoblasts, RBC/WBC production, immune system
Expain the “fight or flight” responses role in modulating blood pressure in an emergency
- Rapid response to emergency and trauma
1. Pain, fear, low BP
2. Hypothalamus activates the SNS, which activate norepinephrine
3. adrenal medulla releases epinephrine into the blood
4. Bind to adrenergic receptors in the HEART, and cause increased HR and strength, which increases BP
5. Bind to adrenergic receptors in the BLOOD VESSELS to cause vasoconstriction in the skin, guts and kidneys, which increases BP
How is cortisol released into the blood stream?
- Hypothalamus releases corticotropin releasing hormone
- Which stimulates the anterior pituitary glad to release ACTH
- Which stimulates the adrenal cortex to release CORTISOL
What occurs in the immune system of someone undergoing extreme stress?
- decreased immune cell production
- decreased thymus activity (fewer T-lymphocytes)
- inflammatory mediators and cytokines are released, which interfere with brain activity
What factors affect an individuals ability to adapt to a stressful situation?
- Physiologic reserve
- ability of body systems to increase their function to react to stress, change in homeostasis - Anatomic Reserve
- paired organs
- Time available
- age, gender
- health status
- sleep-wake cycles
Define hardiness
the ability to conceptualize stressors as a challenge rather than a threat
How does acute stress affect the ANS?
arousal, alertness, vigilance, cognition, focus, aggression. This can be an issue if an individual has pre-existing health problem that causes the ANS to be “pushed”, like heart failure
When might a chronic stress response occur?
- when a component of the system fails
- original stimulus is prolonged, and the individual ability to adapt has been exhausted
Does a chronic stress response result in over-reaction or under-reaction to stress?
either or, different for each person
What manifestations may accompany a chronic stress response?
- necrotizing gingivitis
- herpes simplex
- Rhinovirus
- exacerbation of any disease process
Why does PTSD occur?
a traumatic event causes chronic activation of the stress response
Explain the pathophysiology of PTSD
LOOK THIS UP
- increased catecholamines and thyroid hormones
- decreased cortisol
Explain the PTSD triad
- Intrusion
- flashbacks/nightmares - Avoidance
- emotional numbing
- depression
- survival guilt - Hyperarousal
- irritability/anxiety/insomnia
- exaggerated startle reflex
- difficulty concentration
- memory problems
- overly cautious
PTSD increases the risk for….
- depression
- panic disorders
- anxiety
- substance abuse
- physical illness
What are the treatment options for a patient experiencing PTSD?
- avoid poor coping mechanisms, provide health stress-reducing strategies
- relaxation
- imagery
- music
- massage
- biofeedback
