Structures

  • Sternocleidomastoid
  • Trapezius
  • Splenius capitis
  • Levator scapulae
  • Posterior scalene
  • Middle scalene
  • Anterior scalene
  • Omohyoid

MuscleActionOriginInsertionInnervationBlood supply
Sternocleidomastoid- Rotates head to opposite side
- Sternal fibres extend head
- Clavicular fibres flex head.
- Sternal head: Manubrium of sternum
- Clavicular head: Superomedial clavicle
- Mastoid process
- Superior nuchal line
- Accesory nerve (cranial nerve XI)
- Anterior rami C2-4
- Occipital artery
- Superior thyroid artery
- Posterior auricular artery
Trapezius- Upper fibres: Elevation of scapula and rotation of scapula during humerus abduction
- Middle fibres: Retract the scapula
- Lower fibres: Depress the scapula
- Superior nuchal line
- External occipital protuberance
- Ligamentum nuchae
- Spinous processes of C7-T12
- Lateral 1/3 of clavicle
- Acromion
- Spine of scapula
- Motor: accessory nerve (XI)
- Proprioception: C3,4
- Transverse cervical artery
Splenius capitis- Together: Extend neck
- Individually: Lateral flexion of neck and rotate head to same side
- Lower half of ligamentum nuchae
- Spinous processes of C7-T4
- Mastoid process
- Inferior to lateral superior nuchal line
- Posterior rami C3-6- Occipital artery
Levator scapulae- Elevates scapula- Transverse processes of C1-4- Superomedial border of scapula- Dorsal scapular nerve: C5
- Anterior rami C3,4
- Transverse cervical artery
- Vertebral artery
Posterior scalene- Elevation of 2nd rib- Posterior tubercle of transverse processes of C4-6- Superior surface of 2nd rib- Anterior rami of C5-7- Ascending cervical artery
Middle scalene- Elevation of 1st rib
- Lateral flexion of neck to same side
- Transverse processes of vertebrae CII to CVII- Superior surface of 1st rib- Anterior rami of C3-7-Ascending cervical artery
Anterior scalene- Elevation of 1st rib
- Lateral flexion of neck to same side
- Anterior tubercle of transverse processes of C3-6- Scalene tubercle
- Superior surface of 1st rib
- Anterior rami of C4-7- Ascending cervical artery
Omohyoid- Depresses and fixes hyoid bone- Superior border of scapula medial to suprascapular notch- Lower border of body of hyoid bone - Anterior rami of C1- 3 through the ansa cervicalis- Superior thyroid artery
- Lingual artery
- Superficial cervical artery