Longissimus

Longissimus
Deep muscles of the back. (Longissimus capitis visible at top right; longisimus cervicis visible at center upper right, and longissimus dorsi visible at center right.)
Latin	musculus longissimus
Gray's	subject #115 399
Origin	transverse process
Insertion	transverse process
Artery	lateral sacral artery
Nerve	posterior branch of spinal nerve
Actions	Laterally: Flex the head and neck to the same side. Bilaterally: Extend the vertebral column.
Antagonist	Rectus abdominis muscle

The longissimus is the muscle lateral to the semispinalis. It is the longest subdivision of the sacrospinalis that extends forward into the transverse processes of the posterior cervical vertebrae.

Longissimus thoracis

The Longissimus thoracis is the intermediate and largest of the continuations of the Sacrospinalis.

In the lumbar region, where it is as yet blended with the Iliocostalis lumborum, some of its fibers are attached to the whole length of the posterior surfaces of the transverse processes and the accessory processes of the lumbar vertebræ, and to the anterior layer of the lumbodorsal fascia.

In the thoracic region it is inserted, by rounded tendons, into the tips of the transverse processes of all the thoracic vertebræ, and by fleshy processes into the lower nine or ten ribs between their tubercles and angles.

Longissimus cervicis

The Longissimus cervicis (Transversalis cervicis), situated medial to the Longissimus dorsi, arises by long thin tendons from the summits of the transverse processes of the upper four or five thoracic vertebræ, and is inserted by similar tendons into the posterior tubercles of the transverse processes of the cervical vertebrae from the second to the sixth inclusive.

Longissimus capitis

The Longissimus capitis (Trachelomastoid muscle) lies medial to the Longissimus cervicis, between it and the Semispinalis capitis.

It arises by tendons from the transverse processes of the upper four or five thoracic vertebræ, and the articular processes of the lower three or four cervical vertebrae, and is inserted into the posterior margin of the mastoid process, beneath the Splenius capitis and Sternocleidomastoideus.

It is almost always crossed by a tendinous intersection near its insertion.

See also

• Semispinalis muscle
• Erector spinae
• Spinalis
• Iliocostalis

External links

• SUNY Figs 01:06-05 - "Intrinsic muscles of the back."
• LUC long
• longissimus+%28muscle%29 at eMedicine Dictionary
• Cross section at UV pembody/body12a
• Dissection at ithaca.edu

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained herein may be outdated.

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