lab 8 AOI's Flashcards
Frontalis
A: raises eyebrows
O: epicranial aponeurosis
I: skin of the eyebrows and root of the nose
Occipitalis
A: pulls scalp posteriorly
O: occipital and temporal bones
I: epicranial aponeurosis
Temporalis
A: closes jaw; elevates and retracts mandible
O: temporal fossa
I: coronoid process of mandible
Masseter
A: prime mover of jaw closure, elevated mandible
O: zygomatic arch and zygomatic bone
I: angle and ramus of mandible
Medial pterygoid
A: acts with the lateral pterygoid muscle to protrude mandible and promote side-to-side movements
O: medial surface of lateral pterygoid plate of sphenoid bone; maxilla and palatine bone
I: medial surface of mandible near the angle
Lateral pterygoid
A: provides forward sliding and side-to-side movement of the lower teeth
O: greater wing and lateral pterygoid plate of the sphenoid bone
I: condyle of mandible and temporomandibular joint (TMJ)
Zygomaticus (major)
A: raises lateral corners of the mouth upwards (smiling)
O: zygomatic bone
I: skin and muscle at the corners of the mouth
Buccinator (muscle of mastication)
A: compresses cheek; draws corner of mouth laterally
O: molar region of maxilla and mandible
I: orbicularis oris
Platysma
A: Tenses the skin of neck; depresses mandible
O: fascia of chest
I: lower margin of mandible; skin and muscle at corner of mouth
Orbicularis oculi
A: closes eye; produces blinking and squinting ; draws eyebrows inferiorly
O: frontal and maxillary bones; ligaments around orbit
I: tissue of eyelid
Orbicularis oris
A: closes lips; purses and protrudes lips
O: maxilla and mandible
I: skin and muscle at angles of the mouth
Levator labii superioris
A: opens lips; raises and furrows the upper lip
O: zygomatic bone and infraorbital margin of maxilla
I: skin and muscle of upper lip
Depressor labii inferioris
A: draws lower lip inferiorly
O: body of mandible lateral to its midline
I: skin and muscle of lower lip
Sternocleidomastoid
A: flexes and laterally rotates head; neck flexion and rotation of neck
O: manubrium of sternum; medial portion of clavicle
I: mastoid process of temporal bone; superior nuchal line of occipital bone
Scalenes
A: elevation of ribs 1&2; lateral flexion and rotation of neck
O: transverse processes of C3-7 vertebrae
I: ribs 1-2
Serratus anterior
A: abduction, medial rotation, and stabilization of the scapula
O: ribs 1-8
I: Medial border of scapula
Levator scapulae
A: elevates and adducts scapula
O: transverse processes of C1-C4
I: medial border of scapula, superior to the spine
Rhomboids
A: adduction and elevation of scapula
O: spinous processes of C7- T5 vertebrae
I: medial border of scapula
Splenius
A: rotation of head to the same side; extension of vertebral column; depression of ribs
O: nuchal ligament; spinous processes of C7, T1-T6 vertebrae
I: temporal bone (mastoid process); occipital bone (superior nuchal line); transverse processes of C1-3 vertebrae
Iliocostalis
A: lateral flexion of vertebral column; extension of vertebral column; depression of ribs
O: iliac crest, ribs
I: ribs; transverse process of cervical vertebrae
Semispinalis capitis
A: rotation of head to the opposite side; extension of head and neck
O: transverse processes of C7-T6 vertebrae
I: occipital bone
Long head of triceps
A: forearm extension; stabilizes shoulder joint and assist in arm adduction
O: infraglenoid tubercle of scapula
I: common tendon into olecranon process of ulna
Lateral head of triceps brachii
A: forearm extension
O: posterior shaft of humerus
I: common tendon into olecranon process of ulna
Medial head of the triceps brachii
A: forearm extension
O: posterior humeral shaft distal to radial groove
I: common tendon into olecranon process of ulna
Digastric
A: opens mouth and depresses mandible; elevates hyoid bone and steadys it during swallowing and speech
O: lower margin of mandible; mastoid process of temporal bone
I: hyoid bone
Stylohyoid
A: elevates and retracts hyoid bone during swallowing
O: styloid process of temporal bone
I: hyoid bone
Mylohyoid
A: elevates hyoid bone and floor of mouth
O: medial surface of mandible
I: hyoid bone and median raphe
Geniohyoid
A: pulls hyoid bone superiorly and anteriorly
O: Inner surface of mandibular symphysis (mental tubercle)
I: hyoid bone
Sternohyoid
A: depresses larynx and hyoid bone if mandible is fixed
O: manubrium and medial end of clavicle
I: lower margin of hyoid bone
Sternothyroid
A: pulls larynx and hyoid bone inferiorly
O: posterior surface of manubrium of sternum
I: thyroid cartilage
Thyrohyoid
A: depresses hyoid bone; elevates larynx if hyoid is fixed
O: Thyroid cartilage
I: hyoid bone
Pharyngeal constrictor
A: constricts pharynx during swallowing
O: attached anteriorly to mandible and medial pterygoid plate; hyoid
I: posterior median raphe of pharynx
Genioglossus
A: protracts tongue
O: internal surface of mandible near symphysis (mental tubercle)
I: inferior aspect of the tongue; body of hyoid bone
Hyoglossus
A: depresses tongue; draws its sides downward
O: body and greater horn of hyoid bone
I: inferolateral tongue
Styloglossus
A: retracts and elevates tongue
O: styloid process of temporal bone
I: inferolateral tongue
