Pain Lec 8 and 9 Flashcards
Somatosensory system
- Consists of somatic and propioception
Somatic
Sensations of the skin
Propioception
perception of limb and body positions
Sensory systems
- somatosensory
- special senses
- vision
- hearing
- balance and equilibrium
- taste
- smell
4 elementary attributes involved in coding of a stimulus
- modality
- location
- intensity
- duration
Sensation vs perception
sensation- info that we are aware of
perception - understanding of a stimulus
sensory receptors
-detect specific form of E in the external environment
Modality
energy form of the stimulus
ex. Is the energy from mechanical or light terms?
Different modalities of stimuli and ex
- mechanical: pressure, touch, stretch, acceleration, sound waves
- light
- chemical: taste, smell
- temperature
Law of specific nerve energies
A given sensory receptor is specific for each modality
Receptors respond to adequate stimuli
- of particular modalilty
- within receptive field
- above threshold/ within certain range of intensity
Classes of sensory receptor
- photoreceptors
- chemoreceptors
- thermoreceptors
- mechanoreceptors
Photoreceptors sensation info& modality
- vision
- photons of light
Chemorecs sensation info & modality
- taste
- chemicals dissolved in saliva
- smell
- chemicals dissolved in mucus - pain
- chemicals in extracellular fluid
Thermorecs
sensory and mod
-2 types warm and cold recs
warm- warmth and increase in temp 30-43 degrees
cold- decrease in temp 35-20 degrees
Mechanorecs
sensory and mod
Pacinian corpsucle
- vibration
- pressure
Hair cells
-sound
-sound waves
Balance and equilibrium
- accelerationNociceptors modality
Polymodal
- can have thermo, mechano and chemical recs
Somatic sensation comes from
-skin, muscles, tendons , joints
4 types of somatic sensation
- tactile
- propioception
- temperature
- nociceptors
Tactile sensation includes
- pressure
- touch
- vibration
Propioception includes
- stretch of muscles: spingles
- Force: golgi tendon organ
- also: joints, skin
Temperature includes
- Transient receptor potential ( TRP ) prots
- Cold : less than 17 to 35 degrees
- Warm: 30 to 42 degrees
Nociceptors detect
-noxioud stimuli, noxious mech, noxious temp and some chemicals
