Longus colli muscle

The longus colli is a deep, unpaired, median muscle. Large in size, it is composed of several oblique bundles that lie on the ventral surface of the cervical vertebrae and the first thoracic vertebrae.

Origin: Bodies of the thoracic vertebrae following the first one (thoracic part). Ventral surface of the transverse processes of the last six cervical vertebrae (cervical part).

Insertion: Caudal tubercle of the sixth cervical transverse process (thoracic part). Ventral surface of the most cranial vertebrae, with the bundles converging on the ventral tubercle of the atlas (cervical part).

Relations: Located ventrally to the vertebrae and dorsally to the trachea and esophagus.

Action: Flexor of the neck.

Vascularization: Branches of the vertebral and deep cervical arteries.

Innervation: First intercostal nerves and ventral branches of the cervical nerves.

Description:

Composed of several oblique bundles, their orientation is opposite in the thoracic and cervical parts. In the thoracic part, the bundles converge caudally, while in the cervical part they converge cranially.

Variation:

In Equine, the thoracic part originates beneath the body of the sixth thoracic vertebra and inserts on the transverse process of the sixth cervical vertebra.