anatomy quiz 4

Temporomandibular origin

Temporomandibular origin

Zygomatic arch

Temporomandibular fiber course

Downward and backward

Temporomandibular insertion point

Neck of the condyle

Temporomandibular function

Limits degree to which the condyle can be displaced (downward and backward)

Sphenomandibular origin

Angular spine of the sphenoid bone

Sphenomandibular fiber course

Downward and backward

Sphenomandibular insertion point

Inner surface of the ramus below the condyle

Sphenomandibular function

Limits downward and backward displacement of the mandible

Stylomandibular origin

styloid process

Stylomandibular fiber course

Downward and forward

Stylomandibular insertion point

Near angle of the mandible

Stylomandibular function

Downward and forward displacement of the mandible

Masseter origin

2/3 of the zygomatic arch

Masseter fiber course

Downward and backward

Masseter insertion point

Ramus of the mandible

Masseter function

2 layers:
1. Outer layer - Elevation of the mandible and approximation of the mandible and maxilla
2. Inner layer - Elevation of mandible and pulls backward and approximates jaw

Temporalis origin

Temporal line of the parietal bone and sphenoid bone

Temporalis fiber course

Converge and course downward (Under the zygomatic arch)

Temporalis insertion point

Front surface of the coronoid process and ramus of the mandible

Temporalis function

Upward and backward pull of the mandible. Contraction of one side results in retraction of mandible on activated side

Internal pterygoid origin

Lateral pterygoid plate and the perpendicular plate of the palatine bone

Internal pterygoid fiber course

downward, backward and outward

Internal pterygoid insertion point

Ramus of the mandible

Internal pterygoid function

Elevation of the mandible

External pterygoid origin

2 origins:
1) Greater wing of the sphenoid bone
2) Lateral pterygoid plate

External pterygoid fiber course

2 origins converge and run backwards

External pterygoid insertion point

Neck of the condyle of the mandible

External pterygoid function

Condyle slides downward and forward. Contraction of one side moves front of mandible to the opposite side

Superior longitudinal origin

Root of the tongue from the hyoid bone

Superior longitudinal fiber course

Forward along the axis of the tongue

Superior longitudinal insertion point

Front edges of the tongue and tongue tip

Superior longitudinal function

Shorten tongue and increase convexity from the front to the back

Inferior longitudinal origin

Body of the hyoid bone at the root of the tongue

Inferior longitudinal fiber course

Forward through the body of the tongue

Inferior longitudinal insertion point

Near lower surface of the tongue tip

Inferior longitudinal function

Shortens the tongue and pulls the tongue tip downward

Vertical muscle origin

Beneath the dorsum of the tongue

Vertical muscle fiber course

Downward vertically and toward the side through the body of the tongue

Vertical muscle insertion point

Near the sides of the tongue along the lower surface

Vertical muscle function

Flattens tongue and lowers midline portions of upper tongue surface

Transverse muscle origin

Median fibrous skeleton of tongue

Transverse muscle fiber course

Lateral (side to side within the tongue)

Transverse muscle insertion point

Terminate in the fibrous tissue along the side of the tongue

Transverse muscle function

Narrowing of tongue from side to side and elongating the tongue

Styloglossus origin

Styloid process and stylomandibular ligament

Styloglossus fiber course

Forward, downward and towards the midline

Styloglossus insertion point

Sides of the root of the tongue

Styloglossus function

Draws tongue up and back, shorten tongue, pull tongue tip to the side, brings sides of tongue upward and influences concavity

Palatoglossus origin

Palatal aponeurosis

Palatoglossus fiber course

Downward, forward and to the side

Palatoglossus insertion point

Side of the root of the tongue

Palatoglossus function

Pulls upward, backward and inward on the root of the tongue, displaces tongue mass backwards in oral cavity, increases concavity of upper surface

Hyoglossus origin

Greater cornua of the hyoid bone

Hyoglossus fiber course

Upward and forward

Hyoglossus insertion point

Side of the tongue towards the rear

Hyoglossus function

Lowers body of the tongue and moves it backward

Genioglossus origin

Near midline of the body of the mandible

Genioglossus fiber course

Backward

Genioglossus insertion point (3 groups of muscle)

1) Root of the tongue, 2) juncture between dorsum and blade and 3) the tongue tip

Genioglossus function

1) Brings root of the tongue forward, 2) front of the tongue backwards, 3) center of the tongue pulled downward

Orbicularis oris origin

Concentric rings around the border of the sphincter of the mouth

Orbicularis oris fiber course

Course of fibers change with angular circumference of mouth opening

Orbicularis oris insertion point

The skin and the mucous membrane of the upper and lower lips

Orbicularis oris function

Adduction of the lips, controls the corners of the mouth and pushes lips against teeth

Risorius origin

Fascia of the masseter muscle

Risorius fiber course

Horizontally forward and toward midline

Risorius insertion point

Corner of the mouth and lower lip

Risorius function

Pulls corner of the mouth backward and to the side and forces lips against teeth

Buccinator origin

Pterygomandibular ligament, alveolar process of maxilla, mandible in the region of the molars

Buccinator fiber course

Horizontally forward towards midline

Buccinator insertion point

Upper and lower lip near corners of the mouth

Buccinator function

Pulls corner of mouth backward and to the side as well as forces the lips and cheeks against the teeth