Cranial Nerve Nuclei Columns & Long Tracts Flashcards
GSE
3, 4, 6, 12 (purely motor cranial nerves innervating “garden variety” skeletal muscle)
GVE
Edinger-Westphal (3), Superior Salivatory (7), Inferior Salivatory (9), Dorsal Motor Nucleus of X (10) – preganglionic parasympathetics
SVE
Motor nucleus of V, Motor nucleus of VII, Nucleus Ambiguus (IX, X) (pharyngeal arch derivative muscles, some parasympathetics from X to the heart)
SVA/GVA
Solitary Nucleus (VII, IX, X): tase (upper), carotid sinus and carotid body (lower)
SSA
Vestibular, cochlear nuclei (VIII)
GSA
Trigeminal nuclei: mesencephalic (proprioception from face), main/chief/primary (touch from face); spinal (pain and temperature)
Spinal Trigeminal Nucleus – subparts
Nucleus oralis (facial touch), Nucleus interpolaris (tooth pulp pain), Nucleus caudalis (pain, temperature of face)
Relay nucleus of V
VPM
Medial Lemniscus projects to
VPL of thalamus
Spinothalamic tract projects to
VPL of thalamus
Corticospinal tract descends from
Premotor cortex, Primary motor cortex
Corticobulbar tract
UMNs –> LMN to cranial nerve innervated muscles; generally bilateral innervation
Which cranial nerve is not actually a nerve but a tract of the CNS?
Optic nerve (CN II)
Where do crossing fibers of CST synapse in the cord?
On Alpha or Lower motor neurons in the ventral horn of the cord.
Internal arcuate fibers
ascending fibers from dorsal column nuclei, will form the medial lemniscus after they cross
Difference in lesion @ n. gracilis and medial lemniscus
N. gracilis: loss of vibration, proprioception in ipsilateral lower trunk, lower limb
ML: loss of vibration, proprioception in contralateral trunk & limbs
External (lateral) cuneate nucleus
unconscious proprioception from upper limb –> deep cerebellar nuclei (Mossy fibers)
What nucleus in the cord has a similar function to the external cuneate?
Clarke’s
Where do the axons of the inferior olivary nuclei project & synapse?
The olivary axons cross and project into the contralateral cerebellum and synapse directly with Purkinje cells and send collaterals to the deep Cb nuclei
Reticular formation
The reticular formation is a region in the brainstem that is involved in multiple tasks such as regulating the sleep-wake cycle and filtering incoming stimuli to discriminate irrelevant background stimuli.Important motor axons: central pattern generators
Nuclei that send axons into ICP and their side of origin
Ipsilateral Clarke’s nucleus in the cord, Contralateral inferior olive in the medulla,
Ipsilateral External cuneate nucleus in the medulla, Ipsilateral vestibular nuclei.
input to MCP
pontine nuclei (contralateral)
what axons course in SCP?
Axons exiting the Cb from the deep nuclei and axons entering in the ventral spinocerebellar tract.
Where do axons from SCP project?
Out to various collections of upper motor neurons in the brainstem ( red nucleus, reticular formation) and to the VL nucleus of the thalamus
Lateral lemniscus
The lateral lemniscus is a tract of axons in the brainstem that carries information about sound from the cochlear nucleus to various brainstem nuclei and ultimately the contralateral inferior colliculus of the midbrain.
What are the subdivisions of the substantia nigra and what NTs do they use?
Pars compacta (Dopaminergic neurons) Pars reticularis (GABAergic neurons)
cell bodies of axons in spinal trigeminal tract
trigeminal ganglion
What three cranial nerves send axons into the solitary tract, and what are their functions?
VII, IX, X; taste & carotid body/sinus
What does the anterior thalamic nucleus do?
Receives input from mammillothalamic tract (via mammillary bodies), projects to cingulate gyrus
Uncinate fasciculus
The uncinate fasciculus is a white matter tract in the human brain that connects parts of the limbic system such as the hippocampus and amygdala in the temporal lobe with frontal ones such as the orbitofrontal cortex
