How many scalene muscles are there in the neck?

There are three scalene muscles in the neck: the anterior scalene, middle scalene, and posterior scalene. These muscles are positioned on the lateral aspect of the neck and play crucial roles in the movement and stabilization of the cervical spine. They also function to elevate the first and second ribs during respiration, contributing to the mechanics of breathing.

The anterior scalene originates from the transverse processes of the cervical vertebrae and inserts on the first rib, while the middle scalene has a similar origin but inserts onto the first rib alongside the anterior scalene. The posterior scalene originates from the same cervical vertebrae but is responsible for inserting on the second rib. The distinct roles and anatomical locations of these three muscles highlight their importance in neck stability and respiratory function.