CN V System, Pain Generators, and Processing Flashcards
What are the Peripheral Nociceptive Tissues?
- Meninges
- Skin
- Cornea
- Head, Face, Neck mm.
- LL. of the neck and TMJ
- Vasculature
- Periosteum
What are Peripheral Nociceptive Tissues?
Tissues that carry free nerve endings capable of generating nociceptive stimuli.
What is more important about Peripheral Nociceptive Tissues?
Many of these tissues also have R/C capable of generating stimuli that are inhibitory to the nociceptive stimuli.
What can be concluded about the modulation of Peripheral Nociceptive Tissues?
Either an up regulation of nociception or a down regulation of inhibitory input may contribute to the generation of head and face pain
What can contribute to the generation of head and face pain?
increased A-delta and C-Fiber stimulation or decreased LDA stimulation
What are the three divisions of the Trigeminal Nerve?
V1 - Ophthalmic
V2 - Maxillary
V3 - Mandibular
What are the contributors to the Trigeminal Nerve?
- Cervical Afferents
- Outer Ear contributions from CN VII, IX, X
- Trigemina Ganglion
- Geniculate Ganglion VII
- Superior Ganglia of IX
- Superior Ganglia of X
- Spinal Trigeminal Tract fibers from V, VII, IX, X
What is the cervical afferent contribution to the Trigeminal Nerve?
The convergence of the upper cervical polymodal afferents with the spinal trigeminal nucleus.
Ex: Lack of dermatomal HA distribution
What might cause a nerve to generate pain?
- Compression
- Inflammation
- Infection
- Demyelination
- Deafferentation
- Hypoxia
What are the three main divisions of the trigeminal nuclei?
- Principle Sensory Nucleus
- Spinal Trigeminal Nucleus
- Mesencephalic Nucleus
Where is the principle sensory nucleus located?
Lateral Pons
What does the principle sensory nucleus process?
Fine Touch
Where is the spinal trigeminal nucleus located?
Just caudal to the principle nucleus, it runs to the upper cervical segments and is contiguous with Lamina II
What does the spinal trigeminal nucleus process?
Nociception and Pain
Where is the mesencephalic nucleus located?
Rostral to the principle nucleus into the midbrain
What does the mesencephalic nucleus process?
Proprioception
What is the nociceptive carrying portion of the trigeminal lemniscus?
The Ventral Trigeminothalamic Tract
What are the 2 divisions of the ventral trigeminothalamc tract?
- Paleo-trigeminothalamic Tract
2. Neo-trigeminothalamic Tract
What does the Paleo-Trigeminothalamic tract do?
the P-TT Tract carries the affective aspect of pain.
Where does the Paleo-Trigeminothalmic tract carry information to?
The Frontal Lobe, Anterior Cingulate Gyrus, and Prefrontal Cortex
What does the Neo-Trigemintohalampic Tract do?
The N-TT Tract carries the sensory discriminative aspects of pain.
Where does the Neo-Trigeminothalmic tract carry information to?
The VPM of the Thalamus, the Somatosensory Cortex, and the Anterior Insular Cortex.
What else does the Ventral Trigeminothalmaic Tract do?
Takes Fine Touch, Pressure, and Proprioception more rostrally.
What does the Dorsal Trigeminothalamic Tract do?
Carries fire touch and proprioception ipsilaterally .
Where do the Dorsal and Ventral Trigeminothalamic Tracts join?
The D-TT joins the V-TT rostrally.
What are the Trigeminal Collaterals?
- Hypoglossal Nuc
- Facial Nuc.
- Trigeminal Motor Nuc
- Mesencephalon
- Sup. Salivary Nuc
- Nuc. Ambiguous
- Reticular Fm
- PAG
- Dorsal Motor Nuc of X
What reflex is associated with the Facial Nucleus?
Corneal Reflex
What reflex is associated with the Mesencephalon?
Jaw Jerk Reflex
What reflex is associated with the Dorsal Motor Nuc of X
Vomiting Reflex
What reflex is associated with the Sup Salivatory Nuc?
Lacrimal Reflex
What reflex is associated with the Reticular Fm?
Sneezing Reflex
Which arteries supply the spinal trigeminal tract in the medulla?
The vertebral artery and the PICA
Which arteries supply the spinal trigeminal nucleus in the medulla?
The vertebral artery and the PICA
Which arteries supply the spinal trigeminal tract in the pons?
The basilar artery
Which arteries supply the spinal trigeminal nucleus in the pons?
The basilar artery
Which arteries supply the trigeminothalamic fibers in the midbrain?
The posterior cerebral artery and the superior cerebral artery
Which arteries supply the VPM of the thalamus?
The posterior cerebral artery
Which arteries supply the posterior limb of the internal capsule?
The middle cerebral artery
What constitutes the afferent connection from the cerebral blood vessels to the trigeminal ganglion?
The Trigeminovascular System
What is the efferent effect of the trigeminovascular system hypothesized to contribute to?
The generation of Migraine and Cluster HA’s
Which structure is activated by the Trigeminovascular System with Migraines?
The Meningeal Vasculature
What order neurons bring all sensory information from the head and neck to the thalamus?
2nd Order Neurons
What nucleus in the thalamus receives all sensory input from the head and neck?
The VPM
Where does localization of sensory information from the head and neck occur?
The Lateral Somatosensory Cortex via 3rd Order Neurons
Where is the Trigeminal Motor Nucleus located?
Superior and Medial to the principle sensory nucleus.
Where does the Trigeminal Motor Nucleus have outputs to?
The muscles of mastication
What does the anterior cingulate gyrus play a role in?
The Limbic Control System
Which structure involves interoception?
The Anterior Insular Cortex
Which structure plays a role in affect, executive function, and decision?
The Prefrontal Cortex
