Muscles of the face Flashcards
(27 cards)
Sternocleidomastoid
Origin: Manubrium of sternum; medial 1/3 of clavicle
Insertion: Mastoid process; lateral 1/2 of superior nuchal line
Action:
- Unilateral action tilts head slightly upward and toward the opposite side; rotates head left/right.
- Bilateral action draws head straight forward and down.
- Aids in deep breathing when head is fixed
Longissimus capitis
Origin: Transverse processes of T1-T5; articular processes of C4 or C5-C7
Insertion: Posterior portion of the mastoid process of the temporal bone
Action:
- Bilateral action extends and hyperextends the head
- Unilateral action laterally flexes and rotates the head to the same side
Semispinalis capitis
Origin: Articular processes of vertebrae C4-C7; transverse processes of T1-T6
Insertion: Occipital bone between nuchal lines; spinous processes of vertebrae C2-C5
Action: Extend and contralaterally rotate head
Splenius capitis
Origin: Inferior occipital protuberance; medial 1/3 of superior nuchal line; nuchal ligament; spinous processes of vertebrae C7-T3 or T4
Insertion: Mastoid process and occipital bone just inferior to superior nuchal line; cervical vertebrae C1-C2 or C3
Action:
- Unilateral action produces ipsilateral flexion and slight rotation of head
- Bilateral action extends head
Omohyoid
Origin: Superior border of scapula
Insertion: Hyoid bone
Action: Depresses hyoid after it has been elevated
Sternohyoid
Origin: Manubrium of sternum; medial end of clavicle
Insertion: Hyoid bone
Action: Depresses hyoid after it has been elevated
Sternothyroid
Origin: Manubrium of sternum; costal cartilage 1
Insertion: Thyroid cartilage of larynx
Action: Depresses larynx after it has been elevated in swallowing and vocalization; aids in singing low notes
Thyrohyoid
Origin: Thyroid cartilage of larynx
Insertion: Hyoid bone
Action: Depresses hyoid; with hyoid fixed, elevates larynx
Stylohyoid
**Origin: ** Styloid process of temporal bone
Insertion: Hyoid bone
Action: Elevates and retracts hyoid, elongating floor of mouth
Geniohyoid
Origin: Inferior mental spine of mandible
Insertion: Hyoid bone
Action: Depresses mandible when hyoid is fixed; elevates and protracts hyoid when mandible is fixed
Genioglossus
Origin: Superior mental spine on posterior surface of mental protuberancde
Insertion: Inferior surface of tongue from root to apex
Action: Unilateral action draws tongue to one side; bilateral action depresses midline of tongue or protrudes tongue
Hyoglossus
Origin: Body and greater horn of hyoid bone
Insertion: Lateral and inferior surfaces of tongue
Action: Depresses tongue
Masseter
Origin: Zygomatic arch
Insertion: Lateral surface of madibular ramus and angle
Action: Elevation of the mandible, with smaller roles in protraction, retraction, and lateral and medial excursion
Temporalis
Origin: Temporal lines and temporal fossa of cranium
Insertion: Coronoid process and anterior border of madibular ramus
Action: Elevation, retraction, and lateral and medial excursion of the mandible
Mylohyoid
Origin: Mylohyoid line near inferior margin
Insertion: Hyoid bone
Action: Spans mandible from side to side and forms floor of mouth; elevates floor of mouth in initial stage of swallowing
Digastric, anterior belly
Origin: Mastoid notch of temporal bone; digastric fossa of mandible
Insertion: Hyoid bone via fascial sling
Action: Depresses mandible when hyoid is fixed; opens mouth widely, elevates hyoid when mandible is fixed
Digastric, posterior belly
Origin: Mastoid notch of temporal bone; digastric fossa of mandible
Insertion: Hyoid bone via fascial sling
Action: Depresses mandible when hyoid is fixed; opens mouth widely, elevates hyoid when mandible is fixed
Platysma
Origin: Fascia of deltoid and pectoralis major
Insertion: Mandible; skin and subcutaneous tissue of lower face
Action: Draws lower lip and angle of mouth downward in expressions of horror and surprise; aid in opening mouth widely
Orbicularis oris
Origin: Modiolus of mouth
Insertion: Submucosa and dermis of lips
Action: Encircles mouth, closes lips, protrudes lips as in kissing; used for speech
Zygomaticus major
Origin: Zygomatic bone
Insertion: Superolateral angle of mouth
Action: Draws angle of mouth upward and laterally in laughing
Mentalis
Origin: Mandible near inferior incisors
Insertion: Skin of chin at mental protuberance
Action: Elevates and protrudes lower lip (pouting); elevates and wrinkles skin of chin
Orbicularis oculi
Origin: Lacrimal bone; adjacent regions of frontal bone and maxilla, medial angle of eyelids
Insertion: Upper and lower eyelids; skin around margin of orbit
Action: Sphincter of teh eyelids; closes eye in blinking, squinting, and sleep; aids in flow of tears across eye
Risorius
Origin: Zygomatic arch; fascia near ear
Insertion: Modiolus
Action: Draws angle of mouth laterally in expressions of laughing, horror, or disdain
Buccinator
Origin: Alveolar processes on lateral surfaces of mandible and maxilla
Insertion: Obicularis oris; submucosa of cheek and lips
Action: Compresses cheek against teeth and gums; directs food between molars; retracts cheek from teeth when mouth is closing; expels air and liquid
