Muscle Action Innervation Origin Insertion
Platysma Assists in depressing the Cervical branch of facial Facial muscles/fascia On skin
lower lip nerve
2nd brachial arch!!!! Tenses skin of neck
Sternocleidomastoid Unilateral contraction: Spinal accessory nerve, Mastoid process of Sternal head – Manubrium
lateral flexion of neck ventral rami of C3 and C4 temporal bone Sterni
External jugular vein is Bilateral contraction: Lateral half of the superior Clavicular head: superior
superficial to it flexion of the neck nuchal line surface of medial third of
clavicle
Trapezius Superior fibers: elevate Medial third of the Lateral third of Clavicle,
scapula superior nuchal line. Acromion
Middle + Inferior fibers: External occipital Spine of the Scapula.
retract and depress the protuberance,
scapula Nuchal ligament
Spinous processes of C7-
T12
Scalenus anterior
JUST IDENTIFY THEM
Scalenus posterior
Stylohyoid Elevates hyoid Facial nerve Styloid processes Hyoid bone
Posterior belly of Facial nerve Mastoid process of the
digastric temporal bone Intermediate tendon goes
Anterior belly of digastric Nerve to mylohyoid (V3) Digastric fossa of to hyoid bone
mandible
Mylohyoid Elevates hyoid + floor of Mylohyoid bone of Hyoid bone
mouth mandible
Depresses mandible
Superior belly of Depresses the hyoid bone Ventral rami of C1 – C3 Intermediate tendon Hyoid bone
omohyoid (via the ansa cervicalis)
Inferior belly of omohyoid Ventral rami of C1 – C2 Scapula Intermediate tendon
(via the ansa cervicalis)
Sternohyoid Depresses hyoid Ansa cervicalis Manubrium of sternum Hyoid bone
Sternothyroid Manubrium sterni Thyroid cartilage
Thyrohyoid Depresses hyoid Ventral rami of C1 Thyroid cartilage Hyoid bone
Cricothyroid Tenses, adducts, elongates External laryngeal Cricoid cartilage Thyroid cartilage
larynx
Occipitofrontalis Elevates eyebrows + Temporal + Posterior Occipital belly: lateral two Epicranial aponeurosis
wrinkles forehead auricular branches of the thirds of superior nuchal
FACIAL NERVE line
Frontal belly: epicranial
aponeurosis
orbicularis oculi Closes eyelids. Facial Medial orbital margin Skin + rim of orbit
Platysma Assists in depressing the Cervical branch of facial Facial muscles/fascia On skin
lower lip nerve
2nd brachial arch!!!! Tenses skin of neck
Sternocleidomastoid Unilateral contraction: Spinal accessory nerve, Mastoid process of Sternal head – Manubrium
lateral flexion of neck ventral rami of C3 and C4 temporal bone Sterni
External jugular vein is Bilateral contraction: Lateral half of the superior Clavicular head: superior
superficial to it flexion of the neck nuchal line surface of medial third of
clavicle
Trapezius Superior fibers: elevate Medial third of the Lateral third of Clavicle,
scapula superior nuchal line. Acromion
Middle + Inferior fibers: External occipital Spine of the Scapula.
retract and depress the protuberance,
scapula Nuchal ligament
Spinous processes of C7-
T12
Scalenus anterior
JUST IDENTIFY THEM
Scalenus posterior
Stylohyoid Elevates hyoid Facial nerve Styloid processes Hyoid bone
Posterior belly of Facial nerve Mastoid process of the
digastric temporal bone Intermediate tendon goes
Anterior belly of digastric Nerve to mylohyoid (V3) Digastric fossa of to hyoid bone
mandible
Mylohyoid Elevates hyoid + floor of Mylohyoid bone of Hyoid bone
mouth mandible
Depresses mandible
Superior belly of Depresses the hyoid bone Ventral rami of C1 – C3 Intermediate tendon Hyoid bone
omohyoid (via the ansa cervicalis)
Inferior belly of omohyoid Ventral rami of C1 – C2 Scapula Intermediate tendon
(via the ansa cervicalis)
Sternohyoid Depresses hyoid Ansa cervicalis Manubrium of sternum Hyoid bone
Sternothyroid Manubrium sterni Thyroid cartilage
Thyrohyoid Depresses hyoid Ventral rami of C1 Thyroid cartilage Hyoid bone
Cricothyroid Tenses, adducts, elongates External laryngeal Cricoid cartilage Thyroid cartilage
larynx
Occipitofrontalis Elevates eyebrows + Temporal + Posterior Occipital belly: lateral two Epicranial aponeurosis
wrinkles forehead auricular branches of the thirds of superior nuchal
FACIAL NERVE line
Frontal belly: epicranial
aponeurosis
orbicularis oculi Closes eyelids. Facial Medial orbital margin Skin + rim of orbit
