Superior trunk of brachial plexus
Truncus superior plexus brachialis
- Synonym: Upper trunk
- Related terms: Superior trunk; Superior trunk; Upper trunk; Brachial plexus : Superior trunk; Upper trunk
Definition
The superior trunk of brachial plexus is situated in the floor of the posterior triangle of the neck and forms part of the supraclavicular portion of the brachial plexus. It is formed by the union of the C5 and C6 nerve roots.
Two major nerve branches originate from the superior trunk of brachial plexus:
Suprascapular nerve (C5, C6): This nerve arises from the superior trunk and innervates the supraspinatus and infraspinatus muscles.
Nerve to the Subclavius (C5, C6): Also branching from the superior trunk, it supplies the subclavius muscle.
The supraclavicular portion of the brachial plexus includes not only the superior trunk but also the middle and inferior trunks. Each trunk, including the superior trunk, further divides into two branches: an anterior division and a posterior division.
References
Polcaro L, Charlick M, Daly DT. Anatomy, Head and Neck: Brachial Plexus. [Updated 2023 Aug 14]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK531473/
Drake, R.L., Vogl, A.W., and Mitchell, A.W.M. (2010). ‘Chapter 2: The Back’, in Gray’s anatomy for students. (2nd ed.) Churchill Livingstone Elsevier, Philadelphia PA 19103, pp.95-99 & Fig. 2.44 & 2.45.
Johnson EO, Vekris M, Demesticha T, Soucacos PN. Neuroanatomy of the brachial plexus: normal and variant anatomy of its formation. Surg Radiol Anat. 2010 Mar;32(3):291-7.
