Touch (L6) Flashcards
(18 cards)
What areas of the body has glaborous skin?
palms, soles of feet, lips
What are the 4 mechanoreceptors?
Meissner Corpuscles, Merkel Complexes, RuffiniOrgans, pacinian Corpuscles
Which mechanoreceptors are close to skin surface?
Meissner corpuscles and merkel complexes
Which mechanoreceptors are deeper in skin?
Ruffini Organs and Pacinian Corpuscles
Touch afferent channels open when there is a force applid to the nerve surface. What type of channels are these?
Force gated channels
What are merkel complexes important for?
Transduction of force
T/F- Touch receptors are innervated by large myelinated axons with cell bodies in sympathetic chain
False- cell bodies in Dorsal Root Ganglia
What are slowly adapting mechanoreceptors?
Merkel Complexes and Ruffini Organs
Where are merkel complexes found and what do they respond to?
Found at tips of epidermal ridges, respond to finger indentation
Where are ruffini organs found and what do they respond do?
Upper dermin,…. sustained response to skin movement
Where are meissner receptors found and what do they respond to?
Near skin surface, and have a transient response to skin movement
Where are pacinian receptors found and what do they respond to?
deep in dermis and hypodermis, transient response to vibration
Which slow adapting receptors are superficial and which are deep?
Superficial- merkel
Deep- ruffini
Which rapidly adapting receptors have high density and which one has low density?
Meissner- high density
Pacinian- low density
Pathways from primary mechanoreceptor afferent to cortex contain how many synapses? Where are they?
2 synapses- at brainstem and hypothalamus
Primary somatosensory cortex contains how many Brodmans areas?
4 areas- 1,2,3a,3b
T/F- Cortical representation adapts to changes whereas cortical territory is plastic.
True
Describe the somatosensory pathway….
Dorsal root sensory ganglions—> spinal cord—> travels in dorsal column white matter —> to dorsal column nuclei (lower brainstem (gracile+cuneate nucleus)—> project across midline to thalamus—> project to somatosensory areas of cerebral cortex
