Sensory Systems (Incl. Physiology of Pain) Flashcards
What structure does a light touch receptor have?
Tactile (Meissner’s) corpuscle
What structure does a touch receptor have?
Tactile (Merkle’s) corpuscle
What structure does a pain receptor have?
Free nerve ending
What structure does a deep pressure receptor have?
Lamellated (Pacinian) corpuscle
What structure does a warmth receptor have?
Ruffini corpuscle
What factors determine acuity?
Density of innervation and size of receptive fields
Which types of sensation are carried in AB (large myelinated)fibres?
Touch, pressure and vibration
Which types of sensation are carried in A delta (small myelinated) fibres?
Cold, ‘fast’ pain and pressure
Which types of sensation are carried in C (unmyelinted) fibres
Warmth and ‘slow’ pain
Which fibres carry proprioception?
Aa and AB
Where do primary afferent fibres enter the CNS?
Dorsal root ganglia and cranial nerve ganglia
What path do mechanoreceptive fibres (Aa and AB) take?
They project straight up the ipsilateral dorsal columns, synapse in the cuneate and gracile nuclei, decussate in the brain stem and project to the reticular formation, thalamus and cortex
What path do thermoreceptive and nociceptive fibres (A delta and C) take?
They synapse in the dorsal horn, cross over the midline in the spinal cord and project up the contralateral spinothalamic tract to the reticular foramen, thalamus and cortex
What effect does damage to the dorsal columns have on the transmission of sensory information?
Loss of touch, vibration and proprioception below the lesion on the ipsilateral side
What effect does damage to the anterolateral quadrant have on the transmission of sensory information?
Loss of nociceptive and temperature sensation below the lesion on the contralateral side
