Accessory cuneate nucleus

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.)
Details
Part of	Medulla oblongata
Identifiers
Latin	nucleus cuneatus accessorius
NeuroNames	hier-765
NeuroLex ID	Accessory cuneate nucleus
TA	A14.1.04.209
FMA	72603
*Anatomical terms of neuroanatomy* [edit on Wikidata]

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 the upper extremity equivalent of Clarke's column.^[1]

Additional images

Anatomy of the medulla

afferent:	Solitary nucleus tract Dorsal respiratory group Gustatory nucleus Vestibular nuclei Lateral Medial Inferior

efferent:	Hypoglossal nucleus Nucleus ambiguus Dorsal nucleus of vagus nerve Inferior salivatory nucleus

Dorsal

Ventral

Dorsal	Sensory Sensory decussation Medial lemniscus Juxtarestiform body Ascending dorsal longitudinal fasciculus Medial longitudinal fasciculus Motor Descending dorsal longitudinal fasciculus Medial longitudinal fasciculus

Ventral	Descending tracts Olivocerebellar tract Rubro-olivary tract

Surface

Front	Pyramid decussation Anterior median fissure Anterolateral sulcus Olive Inferior olivary nucleus

Back	Posterior median sulcus Posterolateral sulcus Area postrema Vagal trigone Hypoglossal trigone Medial eminence Inferior cerebellar peduncle

Sensory/
ascending

1°:	Pacinian corpuscle/Meissner's corpuscle → Posterior column (Gracile fasciculus/Cuneate fasciculus) → Gracile nucleus/Cuneate nucleus

2°:	→ sensory decussation/arcuate fibers (Posterior external arcuate fibers, Internal arcuate fibers) → Medial lemniscus/Trigeminal lemniscus → Thalamus (VPL, VPM)

3°:	→ Posterior limb of internal capsule → Postcentral gyrus

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° (Spinomesencephalic 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 → 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

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

Unconscious proprioception	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)

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