Neck and Muscles for Mastication

Superficial muscles of anterior neck

platysma, sternocleidomastoid

Platysma

Platysma Origin

Skin and fascia overlying pectoralis major and deltoid

Platysma Insertion

Inferior border of mandible and skin of lower face

Platysma Innervation

Facial nerve (CN VII)

Platysma Action

Tenses skin of neck

Sternocleidomastoid

Sternocleidomastoid Origin

Sternal head: Manubrium

Clavicular head: Medial part of clavicle

Sternocleidomastoid Insertion

Mastoid process of temporal bone and lateral portion of superior nuchal line of occipital bone

Sternocleidomastoid Innervation

Accessory nerve (CN XI)

Sternocleidomastoid Action

Unilateral side bending on the same side and rotation to the opposite side

bilateral contraction = flexion of head

Suprahyoid muscles

digastric, stylohyoid, mylohyoid, geniohyoid

Digastric

Digastric Origin

Anterior belly: digastric fossa of mandible

Posterior belly: mastoid process of temporal bone

Digastric Insertion

Intermediate tendon connected to hyoid bone

Digastric Innervention

Anterior belly: Branch of trigeminal nerve (V3)

Posterior belly: Facial nerve (CN VII)

Digastric Action

Elevates hyoid during swallowing

Stylohyoid

Stylohyoid Origin

Styloid process of the temporal bone

Stylohyoid Insertion

hyoid

Stylohyoid Innervation

Facial nerve (CN VII)

Stylohyoid Action

Elevates and retracts hyoid during swallowing

Mylohyoid

Mylohyoid Origin

Mylohyoid line of mandible

Mylohyoid Insertion

hyoid

Mylohyoid Innervation

Branch of trigeminal nerve (V3)

Mylohyoid Action

Elevates hyoid during swallowing

Geniohyoid

Geniohyoid Origin

Inferior mental spine of mandible

Geniohyoid Insertion

Hyoid

Geniohyoid Innervation

C1

Geniohyoid Action

Pulls hyoid antero-superiorly in swallowing

Infrahyoid Muscles

sternohyoid, omohyoid, sternothyroid, thyrohyoid

Sternohyoid

Sternohyoid Origin

Posterior surface of manubrium of sternum and medial clavicle

Sternohyoid Insertion

Hyoid

Sternohyoid Innervation

Ansa cervicalis (C1-3)

Sternohyoid Action

Depresses hyoid after elevation during swallowing

Sternothyroid

Sternothyroid Origin

Manubrium of sternum

Sternothyroid Insertion

Oblique line of thyroid cartilage

Sternothyroid Innervation

Ansa cervicalis (C1-C3)

Sternothyroid Action

Depresses thyroid cartilage after elevation during swallowing

Thyrohyoid

Thyrohyoid Origin

Oblique line of thyroid cartilage

Thyrohyoid Insertion

hyoid

Thyrohyoid Innervation

Ansa cervicalis (C1-C3)

Thyrohyoid Action

Depress hyoid and elevate thyroid

Omohyoid

Omohyoid Origin

Inferior belly: upper border of scapula

Superior belly: intermediate tendon

Omohyoid Insertion

Inferior belly: Intermediate tendon

Superior belly: hyoid

Omohyoid Innervation

Ansa cervacalis (C1-C3)

Omohyoid Action

Depress hyoid during swallowing

Anterior Vertebral Muscles

longus colli

longus capitis

Longus coli

Longus coli Origin

Vertebral bodies

Longus coli Insertion

Vertebral bodies including anterior tubercle of atlas

Longus coli Innervation

Ventral rami of cervical nerves

Longus coli Action

Flexes neck

Longus capitis

Longus capitis Origin

Transverse process of middle cervical vertebrae

Longus capitis Insertion

Basilar part of occipital bone

Longus capitis Innervation

Ventral rami of cervical nerves

Longus capitis Action

Flexes head

Muscles of Posterior Triangle

Anterior scalene

Middle scalene

Posterior scalene

Anterior scalene

Anterior scalene Origin

Anterior tubercles of transverse process of cervical vertebrae

Anterior scalene Insertion

First rib anteriorly

Anterior scalene Innervation

Ventral rami of cervical nerves

Anterior scalene Action

Neck flexion, ipsilateral side bending of neck to same side, rotation to opposite side

Middle scalene

Middle scalene Origin

Posterior tubercles of transverse processes of cervical vertebrae

Middle scalene Insertion

Posterior part of first rib

Middle scalene Innervation

Ventral rami of cervical nerves

Middle scalene Action

Ipsilateral side bending of neck, rotation to opposite side

Posterior scalene

Posterior scalene Origin

Posterior tubercles of transverse processes of cervical vertebrae

Posterior scalene Insertion

Second rib

Posterior scalene Innervention

Ventral rami of cervical nerve

Posterior scalene Action

Side bending of neck to same side

Muscles of Mastication

masseter, temporalis, medial pterygoid, lateral pterygoid

Temporalis

Temporalis Origin

Temporal fossa

Temporalis Insertion

Coronoid process and anterior border of ramus of mandible

Temporalis Innervation

Mandibular branch of the trigeminal nerve (V3)

Temporalis Action

Elevation and retraction of mandible

Masseter

Masseter Origin

Inferior margin of zygomatic arch

Masseter Insertion

Lateral surface of ramus and coronoid process of mandible

Masseter Innervation

Mandibular branch of the trigeminal nerve (V3)

Masseter Action

Elevation and some protraction of mandible

Lateral pterygoid

Lateral pterygoid Origin

Infratemporal surface of greater wing of sphenoid bone and lateral surface of lateral pterhyoid plate

Lateral pterygoid Insertion

Pterygoid fossa, articular disc and capsule of TMJ joint

Lateral pterygoid Innervation

Mandibular branch of the trigeminal nerve (V3)

Lateral pterygoid Action

Protraction, depression, and lateral movement of mandible to opposite side

Medial pterygoid

Medial pterygoid Origin

Medial surface of lateral pterygoid plate and tuberosity of maxilla

Medial pterygoid Insertion

Medial surface of mandible near angle

Medial pterygoid Innervation

Mandibular branch of trigeminal nerve (V3)