trigeminal system
Post on 12-Feb-2016
66 Views
Preview:
DESCRIPTION
TRANSCRIPT
Trigeminal System
https://www1.columbia.edu/sec/itc/hs/medical/neruoanatomy/neuroanat/
Somatic sensory: A007Sensory cranial: F003Sensory cranial: F004
Somatic sensory: A006Somatic sensory: AN01
Useful animations:
Readings: Principles of NS General somatic sensory organization: 447-449Brain stem/cranial nerve review: 873-880Sensory nuclei: 880-882, Fig 44-6
Nociceptors, thermoreceptors, & itch receptors
are bare nerve
endings
Merkel’s receptorMeissner’s corpuscle Pacinian
corpuscle
Bare nerveending
Mechanoreceptors are encapsulated
Dorsal horn
Anterolateral system:spino-thalspino-reticspino-mesen
Components of the trigeminal system
• Spinal nucleus– Caudal nucleus Pain/temp/itch– Interpolar nucleus Pain/reflexes, etc, ???– Oral nucleusReflexes, etc, ???
• Main sensory nucleus Mechanosensation• Mesencephalic nucleus Jaw proprioception• Motor nucleus Jaw muscles
Mesencephalic
Main sensorySpinal trigeminal nuc: oral interpolar caudal
Trigeminalmotor
Organization of the spinal trigeminal nucleus:
caudal nucleus
Ophthalmic divisionMaxillary divisionMandibular division7, 9, & 10
C2
12
3
C2
C2
1
2
3Caudal nucleus
Upper spinal cord
Interpolar nucleus
Spinal trigeminaltract
Caudal nucleus
Output:Marginal zone-->Thalamus, midbrainSubstantia gelatinosa-->interneurons
Input: Small-diameter fibers Marginal zone Substantia gelatinosa
Caudal nucleus
Anterolateralsystem
Spinal trigeminaltract
Main sensory
Trigeminalmotor
Anterolateral/trigeminothal
Medial/trigeminallemniscus
Trigeminallemniscus
Mediallemniscus
MesencephalicNucleus &tract
MesencephalicNucleus &tract
Somatic Sensory Thalamus
Medial dorsal
Ventral posterior (VMpo)
Ventral posterior lateral-VPL (spinal)Ventral posterior medial-VPM (trigem)
Touch Pain
Anterolateral and Trigeminal Systems
Ventral posterior-->Postcentral gyrus •localization
Anterolateral System
Ventral medial post-->Insular •behavioral & •autonomic responses •“Limbic”
Amygdala
Medial dorsal-->Cingulate gyrus •emotional (-valence…) •“Limbic”
Anterolateral and Trigeminal Systems
Pain suppression path
Periaqueductalgray matter
Raphe nuclei(5-HT)
Limbic cortex
-Caudalnucleus
Trigeminal System• Separate components for pain and touch• Brain stem nuclei:
– Caudal nucleus (pain)– Interpolar nucleus (caudal part for pain-mouth)– Oral nucleus (???)– Main sensory nucleus
• 3 Separate thalamic pain nuclei & 1 for touch:– Pain (VPM, VMpo, MD)– Touch (VPM)
• 3 Separate cortical representations:– Postcentral gyrus (localization)– Insular (important for pain)– Cingulate (emotions, esp. for pain)
• Pain suppression system– PAG-->Raphe nuclei (5-HT)-->Caudal nucleus
top related