The dorsal scalene muscle originates from the 3rd to 9th rib (varying between species) to insert to the 3rd to 6th cervical vertebrae in all domestic mammals (except in the horse, and some ov and cap in which this muscle is absent). This muscle is situated laterally from the ventral and middle scalene (so the official denomination "dorsal scalene" may be very confusing).
Origin: 3rd rib (pigs), 45th ribs (ruminants), two heads on from 3-5th rib of 8-9th ribs in carnivores
Insertion: transverse processes of C3-C6th vertebrae
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: Nerve: ventral branches of the cervical and thoracic nerves.