The longus colli muscle is found on the anterior (front) side of the vertebral column in the neck. The muscle connects the atlas (the topmost vertebra of the spine) with the third thoracic vertebra in the upper back.
Broader in the middle than at the ends, the muscle contains three sections: the superior oblique, the inferior oblique, and a vertical portion.
The superior, or upper, oblique connects the anterior arch of the atlas with the transverse processes of the third, fourth, and fifth cervical vertebra with a narrow tendon — a flexible and fibrous tissue that often attaches muscle to bone. (The transverse processes are areas of bone that stick out of the sides of the vertebrae.)
The inferior, or lower, oblique connects the fifth and sixth transverse processes with the first two thoracic vertebrae. This section of the muscle is thicker and arises in the front of the bottom of the muscle.
The vertical portion of the muscle connects the first two thoracic vertebrae with the front of the second, third, and fourth cervical vertebrae.