1103 - Ch 5: Muscles of the Head, neck & face
|sternocleidomastoid (action)|| unilaterally: laterally flex the head and neck to same side. Rotate the head and neck to opposite side.|
bilaterally: flex the head. Assist in inhalation (elevation of rib cage).
|sternocleidomastoid (origin)|| sternal head: top of manubrium.|
clavicular head: medial 1/3 of the clavical.
|sternocleidomastoid (insertion)||Mastoid process of the temporal bone and the lateral portion of superior nuchal line of occiput.|
|sternocleidomastoid (nerve)||spinal accessory.|
|temporalis (action)|| elevate the mandible, (temporomandibular joint)|
retract the mandible at the TMJ
example: clench your jaw
|temporalis (nerve)||deep temporal branch of mandibular nerve.|
|medial pterygoid (action)|| unilaterally: laterally deviate the mandible to the opposite side.|
bilaterally: elevate the mandible and protract the mandible.
|medial pterygoid (nerve)||Trigeminal. (V)|
|lateral pterygoid (action)|| unilaterally: laterally deviates themandible to the opposite side.|
bilaterally: protract the mandible.
|lateral pterygoid (nerve)||Trigeminal. (V)|
|scalenes (anterior, middle, posterior) (action)||elevate upper ribs during inhalation.|
|platysma (action)|| assists in depression of the mandible at the TMJ.|
tighten the fascia of the neck.
|buccinator (action)||tightens corners of lips and keeps food between molars during mastication.|
|corrugator (action)||draws eyebrows medially and inferiorally. (frown muscle)|
|masseter (action)||elevates mandible at TMJ.|
|masseter (nerve)||mandibular nerve.|
|occipitofrontalis (action)||occipitalis: anchor and retract the galea posteriorly. frontalis: raise the eyebrows and wrinkle forehead|
|orbicularis oris (action)||closes the mouth and shapes the lips.|
|orbicularis oris (nerve)||facial.|
|orbicularis oculi (action)||closes the eyelid.|
|orbicularis oculi (nerve)||facial.|