The ventral scalene muscle originates from middle portion of the first rib to the transverse processes of the 6th to 3rd vertebrae.
Origin: middle portion of first rib
Insertion: transverse processes of C3-C6 (Su also C1 and C2)
Action: Draws the neck downward. In unilateral action, to bend the neck sideward. When the neck is fixed, the supracostal part can act in inspiration.
Nerve: ventral branches of the cervical and thoracic nerves.
Note: For many authors and in the Vth NAV, the ventral scalene is not present in carnivores. But in the Miller or for Barone, it is described in carnivores such as the dog. The problem is that the ventral scalene and middle scalene are separated by the brachial plexus (also well seen in human between anterior and middle scalene muscles), and the brachial plexus is located anteriorly to the ventral scalene in carnivores, instead between ventral and middle scalene muscle in other mammals.