Exam 1: Pain Background and Heat

nociception

PNS neurons that detect damage, present in nearly all tissues, can lead to pain

types of noxious stimuli

thermal, chemical, and mechanical

nociception vs. pain

input vs. output

a-beta fibers

large; mylenated; fast conducting; low stimulation threshold; respond to light touch, vibration, and stretching

a-delta fibers

small; lightly mylentated; slow conducting; respond to high-intensity mechanical stimulation; sharp, stabbing, or prickling

c fibers

small; unmylenated, very slow conducting; responds to all types of noxious stimuli

temporal categories of pain

acute and chronic

actue pain

lasts less than 12 months; associated with trauma and disease; pain severity is inverse of duration; well-localized

chronic pain

lasts more than three months; may persist from acute state or appear spontaneously

pattern identification of pain

somatic, visceral, and referred

somatic

body; superficial and deep

visercal

organ; unable to associate with somatic structure or MSK activities

referred pain

pain experienced outside the site of pathology; both somatic and visceral

methods of pain evaluation

body maps, pain rating scales, patient-reported outcome measures (PROMS)

gate control theory

stimulating a-beta fibers to compete with nociceptor fiber (a-delta and c fibers)

increased activity from a-beta fibers —> activated inhibitory IN —> inhibits the T cell —> closes the spinal gate

limitations of gate control theory

does not explain influence of:

• post-synaptic inhibition at the CNS

• higher brain centers on pain perception

endogenous opioid system

opiopeptins; they always have an INHIBITORY effect

limitations of endogenous opioid system

large individual differences

3 basic integumentary functions

protection, regulation, and sensation

two types of skin

thick and thin

• hint: thick does not have hair

Come, Let’s Get a Sun Burn

Corneum

Lucidium

Granulosum

Spinosum

Basale

stratum corneum

outermost layer; dead keratinoytes; desquamation

stratum lucidum

present in thick skin

stratum granulosum

cell death occurs at this layer

stratum spinosum

langerhans cells (responsible for immune response); desmosomal connectors

stratum basale

generates stem cells for the surface layer (keratinocytes)

melanocytes

skin coloration; protection against UV radiation

dermal histology: papillary

thin layer; loose connective tissue; vascular network; temperature regulation; nutrient delivery to epidermis

dermal histology: reticular

deep to papillary; dense irregular connective tissue; contains glands and hair follicles

hypodermis histology

layer of adipose tissue; just superficial to the muscle and contains muscle fascia; common place for infection

accessory organs

• hair follicles

• sebum

• sweat glands

greater temperature differences —>

higher transfer rate

materials with high thermal conductivity —>

higher transfer rate

greater area of contact —>

higher total transfer

rater of temperature chance ____ in proportion to skin thickness

decrease

conduction

physical contact between two substances

example: hot pack

convection

movement of medium around the area

example: GameReady

radiation

transfer of energy form high to low without contact

example: red light/laser

evaporation

drying prrocess of sweat/exhalation changes temperatureco

conversion

change in energy type

example: ultrasound

consensual

cooling/heating a body part by using another area of the body

example: putting a cool towel on the forehead to cool body down

vascular response to cold

vasoconstriction

vasodilation (CIVD)

hunting response

neuromuscular effects of cold

decreased nerve conduction velocity (NVD)

increased pain threshold

decreased pain sensation

decreased spasticity

short cooling: decrease in strength

long cooling: increase in strength

metabolic response to cold

decreased metabolic response

cold depth

skin gets colder than muscle

vascular response to heat

vasodilation

superficial heating agents may NOT reach the depth of the muscles

exercise vs. heating with warming up muscles

exercise + heating > exercise > heating

neuromuscular effects of heating

increased NCV

decreased latency

increase pain threshold

prevent/delay DOMS

strength with deep heating

metabolic response to heat

increased metabolic rate

O₂ dissociation curve

increase in temperate shifts the curve to the right

effect of heat on connective tissue

increased collagen extensibility

increased muscle flexibility

decreased joint stiffness

what cold does to BP, HR, and RR

increases, decrease, decrease

what heat does to BP, HR, and RR

decrease, increase, increase