Accessory cuneate nucleus Information & Accessory cuneate nucleus Links at HealthHaven.com

Brain: Accessory cuneate nucleus

Section of the medulla oblongata at about the middle of the olive. (Accessory cuneate nucleus is not labeled, but cuneate nucleus is labeled at upper right, and the accessory cuneate nucleus would be found lateral to it.)
Latin	nucleus cuneatus accessorius
Part of	Medulla oblongata
NeuroNames	hier-765
NeuroLex ID	birnlex_2634

The accessory cuneate nucleus is located lateral to the cuneate nucleus in the medulla oblongata at the level of the sensory decussation (the crossing fibers of the posterior column/medial lemniscus tract).

It receives input from cervical spinal nerves and transmits that information to the cerebellum.^[1]

These fibers are called cuneocerebellar (cuneate nucleus > cerebellum) fibers.

In this function, the accessory cuneate nucleus is comparable to the upper extremity portion of the posterior spinocerebellar tract.^[2]

[edit] References

Dorsal

Surface	Posterior median sulcus · Posterolateral sulcus · Area postrema · Vagal trigone · Hypoglossal trigone · Medial eminence

Grey: Cranial nuclei	afferent: GVA: VII,IX,X: Solitary/tract/Dorsal respiratory group · SVA: Gustatory nucleus · GSA: VIII-v (Lateral, Medial, Inferior) efferent: GSE: XII · GVE: IX,X,XI: Ambiguus · SVE: X: Dorsal · IX: Inferior salivatory nucleus

Grey: other	Gracile nucleus · Cuneate nucleus · Accessory cuneate nucleus

White: Sensory/ascending	Sensory decussation · Medial lemniscus · Inferior cerebellar peduncle (Juxtarestiform body) · Ascending dorsal longitudinal fasciculus · MLF, III, IV and VI

White: Motor/descending	Descending dorsal longitudinal fasciculus · MLF, III, IV and VI

Ventral

White: Motor/descending	Motor decussation · Olivocerebellar tract · Rubro-olivary tract

Grey matter	Ventral respiratory group · Arcuate nucleus of medulla · Inferior olivary nucleus

Surface	Anterior median fissure · Antero-lateral sulcus · Olive · Pyramid

Grey: Raphe/
reticular

Sensory/
ascending

Fast/lateral	1° (Free nerve ending → A delta fiber) → 2° (Anterior white commissure → Lateral and Anterior Spinothalamic tract → Spinal lemniscus → VPL of Thalamus) → 3° (Postcentral gyrus) → 4° (Posterior parietal cortex) 2° (Spinotectal tract → Superior colliculus of Midbrain tectum)

Slow/medial	1° (Group C nerve fiber → Spinoreticular tract → Reticular formation) → 2° (MD of Thalamus) → 3° (Cingulate cortex)

Motor/
descending

Pyramidal	flexion: Primary motor cortex → Posterior limb of internal capsule → Decussation of pyramids → Corticospinal tract (Lateral, Anterior) → Neuromuscular junction

Extrapyramidal	flexion: Primary motor cortex → Genu of internal capsule → Corticobulbar tract → Facial motor nucleus → Facial muscles flexion: Red nucleus → Rubrospinal tract extension: Vestibulocerebellum → Vestibular nuclei → Vestibulospinal tract extension: Vestibulocerebellum → Reticular formation → Reticulospinal tract Midbrain tectum → Tectospinal tract → muscles of neck

Basal ganglia	direct: 1° (Motor cortex → Striatum) → 2° (GPi) → 3° (Lenticular fasciculus/Ansa lenticularis → Thalamic fasciculus → VL of Thalamus) → 4° (Thalamocortical radiations → Supplementary motor area) → 5° (Motor cortex) indirect: 1° (Motor cortex → Striatum) → 2° (GPe) → 3° (Subthalamic fasciculus → Subthalamic nucleus) → 4° (Subthalamic fasciculus → GPi) → 5° (Lenticular fasciculus/Ansa lenticularis → Thalamic fasciculus → VL of Thalamus) → 6° (Thalamocortical radiations → Supplementary motor area) → 7° (Motor cortex) nigrostriatal pathway: Pars compacta → Striatum

Afferent

Efferent

Bidirectional:
Spinocerebellar

Unc. prop.	lower limb → 1° (muscle spindles → DRG) → 2° (Posterior thoracic nucleus → Dorsal/posterior spinocerebellar tract → ICP → Cerebellar vermis) upper limb → 1° (muscle spindles → DRG) → 2° (Accessory cuneate nucleus → Cuneocerebellar tract → ICP → Anterior lobe of cerebellum)

Reflex arc	lower limb → 1° (Golgi tendon organ) → 2° (Ventral/anterior spinocerebellar tract→ SCP → Cerebellar vermis) upper limb → 1° (Golgi tendon organ) → 2° (Rostral spinocerebellar tract → ICP → Cerebellum)

see also white matter fibers