Neuro 3 - Sensation, Neuronal Inclusions

gsafsaf's version from 2015-05-25 19:19

Sensory corpuscles/fibers

Question Answer
MerkelSlowly adaptive receptors; myelinated
MerkelStatic pressure, texture, position sense
MerkelWide distribution; skin layers (finger tips); hairy skin + hair follicles
MerkelLook like melanocytes under microscope
MeissnerRapidly adaptive receptors; myelinated
MeissnerSensitivity to light touch, detect dynamic changes - discriminatory touch
MeissnerFingertips just beneath the epidermis, superficial
Ruffini endingsSpindle-shaped under microscope
Ruffini endingsSlowly adaptive receptors
Ruffini endingsSubcutaneous tissue
Ruffini endingsSensitive to skin stretch; helps in position sense (control of finger/join position/movement)
Pacinianaka Lamellar corpuscles
PacinianRapidly adaptive receptors; myelinated
PacinianDeeper tissues
PacinianDetect vibration and dynamic pressure
PacinianOnion-like pattern under microscope
Free nerve endingsUnspecialized; detect pain + temp.
Free nerve endingsNo complex sensory structures - generic
Free nerve endingsEpidermis
Free nerve endingsVarying rate of adaptation depending on nerve fiber attached to it
A-Delta FiberAttached to free nerve endings; Myelinated; send very fast signals back to the brain
A-Delta FiberPricking pain, detect cold temperatures
Group C nerve fiberAttached to free nerve endings; Unmyelinated; transmit information slowly
Group C nerve fiberANS (postganglionic fibers)
Group C nerve fiber"neuropathic" - sense burning/warmth/itch or dull pain
Slowly adapting sensorSends a continuous electrical signal throughout a continuous stimulus
Rapidly adapting sensorSends an electrical signal only at the beginning and end of a continuous stimulus; "on/off"
Intrafusal muscle fibersMuscles; measures rate of change in length of muscle; help detect body position and regulate rate at which muscle contracts
Golgi tendon organMuscles; detects tension of muscle

Neuronal inclusions

Question Answer
Intranuclear inclusions seen in herpes simplex encephalitisCowdry type A
Cytoplasmic inclusions pathognomonic of rabiesNegri bodies
Neuronal inclusions characteristic of Parkinson diseaseLewy bodies
Cytoplasmic inclusion bodies associated with agingLipofuscin granules
Dark cytoplasmic pigment in neurons of the substantial nigra and locus cereleus NOT seen in Parkinsons ptsMelanin
Eosinophilic, rod-like inclusions in hippocampus of Alzheimer patientsHirano bodies
Diagnostic of Alzheimer diseaseNeurofibrillary plaques and tangles (made of tau protein)
Filamentous inclusions that stain with PAS + ubiquitinLewy Bodies
Intracellular spherical inclusions of tau protein seen on silver stainPick bodies