Many muscles are involved in facial expressions, chewing and speaking. Only the main muscles of the neck will be presented.
Muscle | Origin | Insertion | Action |
Anterior Scalene | anterior tubercles of the transverse processes of vertebrae C3-C6 | scalene tubercle of the first rib | elevates the first rib; flexes and laterally bends the neck |
Middle Scalene | posterior tubercles of the transverse processes of vertebrae C2-C7 | upper surface of the first rib behind the subclavian artery | elevates the first rib; flexes and laterally bends the neck |
Posterior Scalene | posterior tubercles of the transverse processes of vertebrae C5-C7 | lateral surface of the second rib | elevates the second rib; flexes and laterally bends the neck |
Levator Scapulae | transverse processes of C1-4 vertebrae | medial border of the scapula from the superior angle to the spine | elevates scapula |
Splenius | ligamentum nuchae and spines C7-T6 | capitis: mastoid process & superior nuchal line laterally; cervicis: posterior tubercles of C1-3 | extends and laterally bends neck and head; rotates head to same side |
Sternocleidomastoid | sternal head: anterior surface of the manubrium; clavicular head: medial 1/3rd of the clavicle | mastoid process and lateral 1/2 of the superior nuchal line | draws the mastoid process down toward the same side which causes the chin to turn up toward the opposite side; acting together, the muscles of the two sides flex the neck |