Gracile tubercle

Tuberculum gracile

  • Latin synonym: Tuberculum nuclei gracilis

Definition

Muhammad A. Javaid

Gracile tubercle appears as an elevation or a bump on the dorsal surface of the medulla oblongata, in the floor of the fourth ventricle. This prominence is formed by the underlying gracile nucleus, which is a key component of the dorsal column-medial lemniscal sensory pathway.

Lateral to the gracile tubercle lies the cuneate tubercle, a similar elevation also located in the floor of the fourth ventricle. This prominence is formed by the underlying cuneate nucleus, which, like the gracile nucleus, participates in the dorsal column-medial lemniscal pathway.

Both the gracile and cuneate nuclei relay sensory information such as vibration, conscious proprioception, and two-point discrimination. While these nuclei share functional roles within this pathway, they differ in their input sources: the gracile nucleus receives sensory input from the lower extremities, whereas the cuneate nucleus processes input from the upper extremities, excluding the head.

References

  • Chopra, S. and Tadi, P. Neuroanatomy, Nucleus Gracilis. 2021 Jul 28. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan–. PMID: 31536247. https://pubmed.ncbi.nlm.nih.gov/31536247/

  • Snell, R.S. (2010). ‘Chapter 4: The Spinal Cord and the Ascending and Descending Tracts, in Clinical Neuroanatomy. (7th ed.) Philadelphia: Wolters Kluwer Health/Lippincott Williams & Wilkins, pp. 149-151.

  • Al-Chalabi, M., Reddy, V. and Alsalman, I. Neuroanatomy, Posterior Column (Dorsal Column). 2021 Jul 31. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan–. PMID: 29939665. https://pubmed.ncbi.nlm.nih.gov/29939665/

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