Semispinalis Capitis
Original Editor - Scott Buxton
Lead Editors - Venus Pagare, Scott Buxton, WikiSysop, Kim Jackson, Admin and Lucinda hampton
Description
Semispinalis Capitus belongs to the semispinalis muscle group, which in turn is part of the Transversospinal group of muscles (formed of muscles between a spinous process and the transverse process of the vertebrae below) .
The semispinalis muscles have the longest fascicles of transversospinalis group, spanning six segments. The muscles in this group are the semispinalis capitis, semispinalis cervicis, and the semispinalis thoracis.
The semispinalis capitis is a long slender muscle which provided a long moment arm to provide efficient extension.
Anatomy
Origin
The muscle originates on the articular processes of the C 5, 6, 7 and 8 as well as the transverse processes of T 1, 2 ,3 ,4 ,5 and 6.
Insertion
The semispinalis capitis attaches onto the occiput inbetween the superior and inferior nuchal line.
Nerve and Blood Supply
Nerve supply - Greater occipital nerve, which additionally innervates the scalp[1].
Blood supply -Descending branches of the occipital artery and the superior intercostal artery, via the dorsal rami of the upper two posterior intercostal arteries [2]
Action
- Acting bilaterally : Extension of the head and neck.
- Acting unilaterally : Rotation of head and neck to opposite side
Function
During bilateral contraction this muscle is considered as a prime mover for dynamically maintaining the cervical lordosis[3]. It is also considered as one of the main factors in maintaining the balance of the head on the neck[4]
References
- ↑ Natsis K, Baraliakos X, Appell HJ, Tsikaras P, Gigis I, Koebke J. The course of the greater occipital nerve in the suboccipital region: a proposal for setting landmarks for local anesthesia in patients with occipital neuralgia. Clinical Anatomy. 2006 May;19(4):332-6.
- ↑ http://thewellnessdigest.com/semispinalis-capitis-bac-muscle-origin-insertion-action-innervation/
- ↑ Porterfield JA, DeRosa C. Mechanical neck pain,fckLRperspective in functional anatomy. Philadelphia: WB Saunders, 1995.
- ↑ Sinclair D. Functional anatomy, fifth edition.fckLRLondon: B.S. Publication, 1975