Facial muscle

What is unique about muscles of facial expression?

They insert into the skin instead of bone.

Q: What cranial nerve innervates the muscles of facial expression?

A: CN VII (facial nerve).

Where is the buccinator located?

Cheek; forms the wall of the cheek.

Q: Where is the depressor anguli oris located?

A: Lower face; runs from the mandible toward the corner of the mouth.

What is the origin of the depressor anguli oris?

Mandible body.

What is the insertion of the depressor anguli oris?

Skin at angle of mouth.

What is the action of the depressor anguli oris?

Depress angle of mouth; frowning.

Where is the depressor labii inferioris located?

Lower face; below the lower lip.

What is the origin of the depressor labii inferioris?

Mandible body.

What is the insertion of the depressor labii inferioris?

Skin of lower lip.

What is the action of the depressor labii inferioris?

Depress lower lip.

Where is the epicranial aponeurosis (galea aponeurotica) located?

Tendon-like sheet over the top of the skull.

Where is the frontalis located?

Forehead; anterior scalp.

Where is the levator labii superioris located?

Upper face beside the nose; runs toward the upper lip.

Where is the occipitalis located?

Back of the scalp.

Where is the orbicularis oculi located?

Around the eye/orbit.

What is the origin of the orbicularis oculi?

Orbit (eye socket)

What is the insertion of the orbicularis oculi?

Skin of eyelids.

Q: What is the action of the orbicularis oculi?

Close eyelids

Where is the orbicularis oris located?

Circular muscle surrounding the mouth/lips.

What is the origin of the orbicularis oris?

Alveolar processes of maxilla and mandible.

What is the insertion of the orbicularis oris?

Skin of lips.

What is the action of the orbicularis oris?

Close lips/purse lips.

Where is the platysma located?

Thin, superficial muscle covering the front and sides of the neck.

Where is the zygomaticus major located?

Cheek; runs from the zygomatic bone toward the upper lip/corner of mouth.

Where is the zygomaticus minor located?

Cheek; runs from the zygomatic bone toward the upper lip.

What is the origin of the zygomaticus major & minor?

Zygomatic bone.

What is the insertion of the zygomaticus major & minor?

Muscles of upper lips.

What is the action of the zygomaticus major & minor?

Elevates corner of mouth and upper lip.

What cranial nerve innervates the muscles of mastication?

Mandibular branch of CN V (trigeminal).

What is the main function of the muscles of mastication?

Chewing; elevation of mandible.

Where is the masseter located?

Side of the jaw; over the mandibular ramus.

What is the origin of the masseter?

Zygomatic arch.

What is the insertion of the masseter?

Mandibular angle.

What is the action of the masseter?

Elevation of mandible

Where is the temporalis located?

Fan-shaped muscle on the side of the skull, above the ear.

What is the origin of the temporalis?

Temporal lines, parietal bone.

What is the insertion of the temporalis?

Coronoid process of mandible.

What cranial nerve innervates the muscles of the tongue?

CN XII (hypoglossal).

What does "glossus" mean?

Tongue.

Where is the genioglossus located?

Deep in the mouth; runs from the mandible toward the tongue.

What is the origin of the genioglossus?

Medial surface of mandible.

What is the insertion of the genioglossus?

Tongue.

What is the action of the genioglossus?

Protracts tongue; sticking out tongue.

Where is the hyoglossus located?

Side of the tongue; runs from the hyoid toward the tongue.

Where is the styloglossus located?

Runs from the styloid process toward the tongue.

Where is the stylohyoid located?

Neck; runs from the styloid process toward the hyoid bone.

Where is the digastric located?

Under the mandible; has two muscle bellies

Where is the omohyoid located?

Anterior neck; runs from scapula toward hyoid.

Where is the sternocleidomastoid located?

Side of neck; runs from sternum/clavicle to mastoid process.

What is the origin of the sternocleidomastoid?

Sternum and clavicle.

What is the insertion of the sternocleidomastoid?

Mastoid process of temporal bone.

What is the action of the sternocleidomastoid?

Flexion of neck; lateral flexion of neck; rotation of neck.

Where is the sternohyoid located?

Front of neck; runs from sternum toward hyoid.

Where is the sternothyroid located?

Front of neck; runs from sternum toward thyroid cartilage.

Where is the stylohyoid located?

Neck; runs from styloid process toward hyoid.

Where is the aponeurosis of the external abdominal obliques located?

Flat tendon-like sheet covering the front of the abdominal wall.

Where is the diaphragm located?

Dome-shaped muscle separating thoracic and abdominal cavities.

Where is the erector spinae located?

Long muscle group running along both sides of the vertebral column.

Where is the external abdominal oblique located?

Superficial/lateral abdominal wall.

What is the origin of the external abdominal oblique?

Lower ribs.

What is the insertion of the external abdominal oblique?

External abdominal oblique aponeurosis, iliac crest.

What is the action of the external abdominal oblique?

Flexion of torso; lateral flexion of torso; rotation of torso.

Where are the external intercostals located?

Between the ribs; superficial layer.

Where is the internal abdominal oblique located?

Deep to the external abdominal oblique; lateral abdominal wall.

What is the origin of the internal abdominal oblique?

Iliac crest.

What is the insertion of the internal abdominal oblique?

Lower ribs.

Where are the internal intercostals located?

Between the ribs; deep to the external intercostals.

Where is the rectus abdominis located?

Vertical muscle along the front of the abdomen; "six-pack."

What is the origin of the rectus abdominis?

Pubic bone (pubis).

What is the insertion of the rectus abdominis?

Xiphoid process and ribs.

What is the action of the rectus abdominis?

Flexion of torso.

Where are the scalenes located?

Lateral neck; anterior, middle, and posterior muscles.

What is the origin of the scalenes?

Transverse processes of cervical vertebrae.

What is the insertion of the scalenes?

1st or 2nd rib.

What is the action of the scalenes?

Elevate ribs and/or flex neck.

Where is the splenius capitis located?

Posterior neck; runs toward the skull.

Where is the transverse abdominis located?

Deepest abdominal muscle; wraps horizontally around the abdomen.

What does "orbicularis" help you remember?

Circular muscle

What does "depressor" tell you?

Moves something downward

What does "levator" tell you?

Moves something upward

What does "zygomaticus" tell you?

Located around the zygomatic bone/cheek.

What does "glossus" mean?

Tongue

What does "sterno" mean?

Sternum

What does "cleido" mean?

Clavicle

What does "omo" mean?

Scapula.

What does "stylo" mean?

Styloid process

What does "thyroid" refer to?

Thyroid cartilage