Longissimus

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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
Action:
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.

Contents 1 Longissimus dorsi 2 Longissimus cervicis 3 Longissimus capitis 4 See also 5 External links

[edit] Longissimus dorsi

The Longissimus dorsi 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.

[edit] 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.

[edit] 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.

[edit] See also

• Semispinalis muscle
• Erector spinae
• Spinalis
• Iliocostalis

[edit] 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

v • d • e List of muscles of torso BACK splenius (capitis, cervicis) - erector spinae (iliocostalis, longissimus, spinalis) - latissimus dorsi transversospinales: (semispinalis dorsi, semispinalis cervicis, semispinalis capitis, multifidus, rotatores) - interspinales - intertransversarii SUBOCCIPITAL rectus capitis posterior (major, minor) - obliquus capitis (inferior, superior) CHEST intercostales (external, internal, innermost) - subcostales - transversus thoracis - levatores costarum - serratus posterior (inferior, superior) - diaphragm ABDOMEN anterior/lateral wall: obliques (external, internal) - transversus abdominis - rectus abdominis - pyramidalis posterior wall: quadratus lumborum - psoas major/psoas minor - iliacus cremaster PELVIS/FLOOR levator ani (iliococcygeus, pubococcygeus, puborectalis) - coccygeus PERINEUM anal triangle: sphincter ani (externus, internus) superficial perineal pouch (superficial transverse perineal, bulbospongiosus, ischiocavernosus) deep perineal pouch (deep transverse perineal, sphincter urethrae membranaceae)

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. Please edit the article if this is the case, and feel free to remove this notice when it is no longer relevant.