The Somatosensory System Flashcards
What is somatosensory sensation?
Cutaneous sensation
What does the Meissner corpuscle detect?
Mechanoreceptors that respond to light touch and texture.
What does the Pacinian corpuscle detect?
Pressure and rapid vibration
What do Merkel’s discs respond to?
Sustained touch and pressure
What do Ruffini’s corpuscles detect?
Detect stretch
What do free nerve ending’s detect?
Pain, temperature, mechanical deformation (all types basically)
What do hair follicle receptors detect?
Movement
What aids proprioception?
Stretch receptors and muscle spindles are responsible for proprioception.
What is the difference between fast adaptation and slow adaptation receptors?
Fast adaptation have a brief response.
Slow adaptation respond and detect stimuli for longer before eventually fading.
Which type of neuron fibre are unmyelinated?
Type C
What type of somatosensory sensation decussate?
Pain and temperature decussates
Pain and temperature travels in what spinal tract?
Spinothalamic tract
Where in the brain do somatosensory impulses travel to?
Post-central gyrus / primary somatosensory area
An innocuous mechanical stimulus travels through what nerve fibre?
Aß fibers
A noxious mechanical stimulus travels through what type of nerve fiber?
Adelta fiber
Pain and thermal stimuli travels along what type of nerve fibre?
Type C fibre
How do reflex arcs work?
Directly connect sensory neurons to motor neurons, bypassing the CNS.
How does referred pain work?
Shared dorsal root ganglia, so a dorsal root ganglia in the heart for example is also gives sensory innervation to left arm.
Thus a pain in the heart is also detected in the left arm.
What type of sensation travels along type C nerve fibres?
Pain and thermal stimuli
What type of sensation travels along Aß nerve fibres?
Innocuous mechanical sensation
What type of sensation travels along type Adelta nerve fibres?
Noxious mechanical stimuli
