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
Details
Latin	musculus longissimus
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
Identifiers
Gray's	p.399
TA	A04.3.02.010
FMA	77178
Anatomical terms of 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.

Structure

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.

External links

Anatomy figure: 01:06-05 at Human Anatomy Online, SUNY Downstate Medical Center - "Intrinsic muscles of the back."
longissimus+%28muscle%29 at eMedicine Dictionary
Cross section image: pembody/body12a - Plastination Laboratory at the Medical University of Vienna
Dissection at ithaca.edu

Muscles of thorax and back

Back

splenius	capitis cervicis

erector spinae	iliocostalis longissimus spinalis latissimus dorsi

transversospinales	semispinalis dorsi semispinalis cervicis semispinalis capitis multifidus rotatores interspinales intertransversarii

Vertebral column	trapezius latissimus dorsi rhomboid major minor levator scapulae

Fascia	thoracolumbar fascia

Thorax

Intercostal muscle external internal innermost subcostalis transversus thoracis levatores costarum serratus posterior inferior superior thoracic diaphragm

Thoracic cavity	pectoralis major pectoralis minor subclavius serratus anterior sternalis

Fascia	pectoral fascia clavipectoral fascia

Index of muscle

Description	Anatomy head neck arms chest and back diaphragm abdomen genital area legs Muscle tissue Physiology connective tissue

Disease	Myopathy Soft tissue Connective tissue Congenital abdomen muscular dystrophy Neoplasms and cancer Injury Symptoms and signs eponymous

Treatment	Procedures Drugs anti-inflammatory muscle relaxants

References

This article incorporates text in the public domain from the 20th edition of Gray's Anatomy (1918)