Musculature Flashcards
Platysma origin
fascia of superior portions of pectoralis major and deltoid
Platysma insertion
1) inferior mandible at symphysis
2) skin and fascia of the lower parts of the face
Platysma action
1) wrinkles the skin of the neck and upper chest
2) depresses the corners of the mouth
Sternocleidomastoid origin
(pl. sternocleidomastoideus)
1) medial head: manubrium of the sternum
2) lateral head: middle 1/3 of the clavicle
Sternocleidomastoid insertion
mastoid process of temporal bone
Sternocleidomastoid action
1) bilateral: flexes the neck (anteriorly), elevates sternum during forced inspiration
2) unilateral: contralateral rotation of the head, ipsilateral flexion of the neck
Digastric attachments
(pl. digastricus)
1) anterior belly: digastric fossa of internal mandible
2) posterior belly: mastoid process of temporal bone
- both bellies meet and attach at the lateral aspect of the body of the hyoid bone by a pulley tendon
Digastric action
1) opens mouth by depressing mandible
2) elevates hyoid bone
Mylohyoid (pl. mylohyoideus)
origin
Inner surface of mandible
Mylohyoid (pl. mylohyoideus)
insertion
1) body of hyoid
2) along midline at mylohyoid raphe
Mylohyoid (pl. mylohyoideus)
action
1) elevates the hyoid bone
2) raises floor of mouth (for swallowing)
Stylohyoid (stylohyoideus)
origin
Styloid process of temporal bone
Stylohyoid (stylohyoideus)
insertion
lateral margin of hyoid (near greater horn)
Stylohyoid (stylohyoideus)
action
pulls the hyoid superiorly and posteriorly during swallowing
Sternohyoid (sternohyoideus)
Origin
1) manubrium of sternum
2) medial end of clavicle
Sternohyoid (sternohyoideus)
insertion
body of hyoid bone
Sternohyoid (sternohyoideus)
action
Depresses hyoid bone
Sternothyroid (sternothyroideus)
origin
Manubrium of sternum
Sternothyroid (sternothyroideus)
insertion
thyroid cartilage of larynx
Sternothyroid (sternothyroideus)
action
depresses thyroid cartilage
Thyrohyoid (thyrohyoideus)
origin
Thyroid cartilage of larynx
Thyrohyoid (thyrohyoideus)
insertion
greater horn of hyoid bone
Thyrohyoid (thyrohyoideus)
action
1) elevates thyroid cartilage
2) depresses hyoid bone
Omohyoid (omohyoideus)
origin
Superior border of scapula
Omohyoid (omohyoideus)
insertion
body of hyoid bone, lateral to the insertion of sternohyoid
Omohyoid (omohyoideus)
action
depresses hyoid bone
Frontalis origin
Epicranial aponeurosis
Frontalis insertion
skin above the eyebrows
Frontalis action
1) elevates the eyebrows
2) produces horizontal wrinkles the skin of the forehead
Masseter origin
1) superficial portion: zygomatic process of maxilla
2) deep portion: zygomatic arch
Masseter insertion
superficial portion: angle of ramus of mandible
deep portion: upper portion of ramus and coronoid process of mandible
Masseter action
close the jaw by elevating the mandible
Temporalis origin
Temporal fossa of skull
Temporalis insertion
coronoid process and ramus of mandible
Temporalis action
closes the jaw by elevating the mandible
Buccinator origin
1) alveolar process of maxilla and mandible
2) pterygomandibular raphe
Buccinator insertion
fibers of orbicularis or is at the lateral aspect of the mouth
Buccinator action
compresses the cheek, to hold food between the cheek and teeth
Orbicularis Oris origin
Very complex; maxilla and mandible, in roughly 4 quadrants
Orbicularis Oris insertion
skin around the lips
Orbicularis Oris action
constricts the opening of the mouth (puckers lips)
Orbicularis oculi origin
medial portion of the orbit
Orbicularis oculi insertion
skin of the eyelid
Orbicularis oculi action
1) tightly closes eyelids (squint)
2) compresses lacrimal (tear) sac
Levator palpebrae superioris origin
Sphenoid bone
Levator palpebrae superioris
insertion
tarsal plate of upper eyelid
Levator palpebrae superioris
action
retracts and elevates eyelid (open the eye)
Zygomaticus major
origin
antero-lateral aspect of zygomatic bone
Zygomaticus major
insertion
connective tissue of the angle of the mouth
Zygomaticus major
action
draws the angle of the mouth upward and laterally (sincere smile)
Zygomaticus minor
Origin
Anterior-medial aspect of zygomatic bone
Zygomaticus minor
insertion
skin of the upper lip