Structures

  • Sternocleidomastoid
  • Stylohyoid
  • Digastric
  • Mylohyoid
  • Geniohyoid
  • Sternohyoid
  • Thyrohyoid
  • Sternothyroid

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
Stylohyoid- Pulls hyoid bone posterosuperiorly- Base of styloid process- Lateral portion of body of hyoid bone- Facial nerve (cranial nerve VII)- Superior thyroid artery
- Lingual artery
Digastric:
-Anterior belly
- Posterior belly
- Opens mouth by depressing mandible
- Raises hyoid bone
- Anterior belly: Digastric fossa on inferodorsal mandible
- Posterior belly: Mastoid process of temporal bone
- Body of hyoid bone- Anterior Belly: Mandibular branch of trigeminal nerve (cranial nerve V)
- Posterior belly: Facial nerve (cranial nerve VII)
- Anterior belly: Facial artery and inferior alveolar artery
- Posterior belly: Occipital artery
Mylohyoid- Elevation of floor of mouth;
- Elevation of hyoid
- Mylohyoid line on mandible- Body of hyoid bone - Mandibular branch of trigeminal nerve (cranial nerve V)- Lingual artery
- Inferior alveolar artery
- Facial artery
Geniohyoid- Elevation of the unfixed hyoid bone
- Depression of mandible when fixed hyoid bone
- Inferior mental spine on posterior surface of mandible- Anterior surface of body of hyoid bone- Branch from anterior ramus of C1 (carried along the hypoglossal nerve [XII])- Sublingual artery
- Facial artery
- Inferior alveolar artery
Sternohyoid- Depresses hyoid bone after swallowing- Posterior sternoclavicular joint
- Manubrium of sternum
- Body of hyoid bone - Anterior rami of C1-3 via the ansa cervicalis- Superior thyroid artery
- Lingual artery
- Superficial cervical artery
ThyrohyoidDepresses hyoid bone, but when hyoid bone is fixed raises larynxOblique line on lamina of thyroid cartilageGreater horn and adjacent aspect of body of hyoid boneFibers from anterior ramus of C1 carried along hypoglossal nerve [XII]- Superior thyroid artery
- Lingual artery
- Inferior thyroid artery
SternothyroidDraws larynx (thyroid cartilage) downwardPosterior surface of manubrium of sternumOblique line on lamina of thyroid cartilageAnterior rami of C1 to C3 through the ansa cervicalis- Superior thyroid artery
- Lingual artery
- Inferior thyroid artery