Neuro Lab 8 Flashcards
Precentral Gyrus
Primary motor area
Premotor cortex
Motor neurons related to indirect (extrapyramidal) motor pathways
Superior frontal gyrus
Supplementary motor area
Middle frontal gyrus (caudal area)
Frontal eye fields
Paracentral lobule
Medial continuation of primary motor and sensory areas
Internal capsule (posterior limb)
Contains axons of corticobulbar, corticospinal, and corticopontine neurons and the thalamocortical neurons. Separates the thalamus from lentiform nucleus. Part of major pathway for sensory and motor neurons.
Caudate nucleus (head, body, tail)
Part of striatum, extends from floor of anterior horn to the roof of the temporal horn of the lateral ventricle
Putamen
Part of the striatum, most lateral portion of the lentiform nucleus (lateral to globus pallidus)
Globus pallidus
Part of striatum, most medial portion of the lentiform nucleus, immediately lateral to the internal capsule
Internal capsule (anterior limb)
Separates caudate nucleus from the lentiform nucleus. Part of major pathway for sensory and motor neurons
Internal capsule (genu)
Adjacent to the interventricular foramen. Part of major pathway for sensory and motor neurons.
Thalamus
Contains major motor and sensory relay nuclei in diencephalon. Located medial to posterior limb of the internal capsule.
Lenticular fasciculus
Nerve fiber bundle (pallidothalamic neurons) running from globus pallidus to ventral anterior and lateral thalamic nuclei
Ventral lateral thalamic nucleus
Motor nucleus of the thalamus. Input of the cerebellum via cerebello-rubro-thalamic tract (superior cerebellar peduncle) and from globus pallidus internum
Subthalamic nucleus
Medial to internal capsule. Involved in indirect basal ganglia pathway, lesions of subthalamic region lead to hemiballismus
Oculomotor nucleus
Contains motor neurons to 5 extraocular eye muscles
Cerebral crus
Major motor pathway from cerebrum, includes corticospinal, corticobulbar, and corticopontine neurons
Corticobulbar tract
Cell bodies in precentral gyrus, axons through internal capsule and cerebral crus to reach motor neurons in the bulb
Corticospinal tract
Cell bodies in cerebral cortex. Axons pass through internal capsule, cerebral crus, basilar pons, pyramids to form ventral and lateral corticospinal tract in spinal cord.
Corticopontine tract
Cell bodies in the cerebral cortex. Axons pass through internal capsule and cerebral crus to terminate on pontine nuclei.
Substantia nigra
Black substance (neuromelanin) located dorsal to cerebral crus, contrains the cell bodies of nigrostriatoal neurons
Red nucleus
Located in tegmentum of pons, input from cerebellum and cerebral cortex, gives rise to rubrospinal tract
Trochlear nucleus
Cell bodies of trochlear nerve that innervate SO muscle. Located below inferior colliculus
Decussation of superior cerebellar peduncle
Cerebello-rubro-thalamic fibers of superior colliculus cross in rostral midbrain and terminate in red nucleus and the ventral lateral thalamic nuclei
Middle cerebellar peduncle
Connects pons with cerebellum, contains pontocerebellar fibers whose cell bodies are in the contralateral basilar pons
Superior cerebellar peduncle
Found in roof of 4th ventricle, continues through midbrain, decussates, cerebello-rubro-thalamic fibers terminate in contralateral red nucleus in the ventral lateral thalamic nucleus, contains ventral spinocerebellar fibers
Basilar pons
Pontine nuclei here, corticobulbar and corticospinal fibers transverse
Pontine nuclei
In basilar pons, give rise to pontocerebellar fibers of the middle cerebellar peduncle
Trigeminal motor nucleus
Motor nucleus to muscles of mastication. Medial to the trigeminal main sensory nucleus
Corticospinal, corticobulbar, corticopontine tracts
All arise from pyramidal cells of cerebral cortex,
Corticopontine fibers
Terminate on pontine nuclei
Pontocerebellar tract
Pontine nuclei in basilar pons give rise to pontocerebellar fibers that make up the middle cerebellar peduncle
Abducens nucleus
Motor nucleus associated with facial colliculus, motor neurons to the SO muscle
Facial motor nucleus
Motor nucleus innervated muscles of facial expression
Inferior cerebellar peduncle
Numerous afferent and efferent fibers for cerebellum, dorsal spinocerebellar tract, olivocerebellar fibers, vestibulocerebellar fibers, reticulocerebellar fibers, cerebello-vestibular, corticoreticular etc.
Hypoglossal nucleus
Contains cell bodies of hypoglossal nerve that innervates tongue muscles
Nucleus ambiguus
Motor neurons for CN IX and X, and contains so preganglionic parasympathetic neurons that innervate the heart
Vestibular nuclei
In floor of 4th ventricle. Site of termination of vestibular nerve. Gives rise to medial longitundinal fasciculus and vestibulospinal tract
Inferior olivary nucleus
Contains cell bodies of olibocerebellar neurons that cross to the contralateral cerebellar hemisphere
Olivocerebellar fibers
Originate from contralateral inferior olivary nucleus
Lateral cuneate nucleus
Unconscious proprioception from upper limb. Gets input from cuneate fasciculus. Contains cell bodies of cuneocerebellar fibers that reach cerebellum through inferior cerebellar peduncles
Pyramids
Contains corticospinal fibers from ipsilateral cerebral cortex
Pyramidal decussation
At junction of caudal medulla and spinal cord, most fibers cross and form lateral corticospinal tract in lateral funiculus, while remaining fibers cont. as the ventral corticospinal tract and cross in the ventral white commissure before terminating in the contralateral ventral horn
Accessory nucleus
Motor nucleus innervating SCM and trapezius muscles
Lateral column
Contains lateral corticospinal tract, spinothalamic tract and dorsal and ventral spinothalamic tracts are present
Ventral column
Contains ventral corticospinal tract, medial longitudinal fasciculus in the cervical region, vestibulospinal, reticulospinal etc. tracts involved in reflex activity
Ventral white commissure
Site of crossing of the ventral spinothalami tracts and spinothalamic fibers
Dorsal horn
Sensory horn of the spinal cord, neurons give rise ot ascending sensory pathways
Intermediate gray
Located between dorsal and ventral horns
Ventral horn
Motor horn of the spinal cord, neurons give rise to LMN (alpha and gamma motor neuron)
Lateral corticospinal tract
Motor fibers located in the lateral funiculus
Ventral corticospinal tract
Motor fibers located in the ventral funiculus
Dorsal spinocerebellar tract
Unconscious proprioceptive neurons that arise from ipsilateral Clarke’s nucleus and ascend to the cerebellum
Ventral spinocerebelar tract
Unconscious proprioceptive neurons that arise from cells in the posterior horn that crosses to the contralateral side and ascend to the cerebellum
Clarke’s Nucleus (nucleus dorsalis)
Contains cell bodies of neurons that give rise to ipsilateral dorsal spinocerebellar tract
Lateral motor cell column
Column of motor neurons in the ventral horn that innervate appendicular muscles
Medial motor cell column
Column of motor neurons in ventral horn that innervate axial muscles
Posterior lobe
Part of cerebellum between the primary fissure and the posterolateral fissure
Tonsil
Part of posterior lobe near foramen magnum
Posterolateral fissure
Separates flocculonodular lobe from posterior lobe
Flocculonodular lobe
Concerned with vestibular function
Anterior lobe
Part of cerebellum anterior to primary fissure
Primary fissure
Separates anterior lobe from posterior lobe
Vermal zone
Involved in motor control, on either side of midline in cerebellum
Paravermal zone
Area on either side lateral to the vermal area, involved in motor control
Lateral zone
Lateral to paravermal area. Receives major imnput from pontocerebellar neuron and purkinje cells in lateral hemispheres project especially into the dentate nucelus. Dentato-rubro-thalamic pathway conveys primary output from the cerebellum
Deep cerebellar nucleu
Dentate, emboliform, globus, fastigial
