Zygomatic Bone Essay
The SKULL
CRANIUM (SKULL) * skeleton of the head
2 Parts * Neurocranium * Viscerocranium
1. Neurocranium * cranial vault * bony case of the brain * has a dome like roof -calvaria or skullcap * has a floor or cranial base –Basicranium * these are irregular bones with flat portions * formed by a series of 8 bones * Frontal * Ethmoidal * Sphenoidal * Occipital * Temporal (2sets) * Parietal (2 sets)
2. Viscerocranium * facial skeleton * forms the anterior part of the cranium * consists of bones surrounding the orbits, nose and mouth * consists of 15 irregular bones * Mandible * Ethmoid * Vomer * Maxillae * Zygomatic * Palatine …show more content…
INSERTION * angle of mouth
ACTION * part of dilators of mouth * elevates labial commissure bilaterally to smile (happiness) * unilaterally to sneer (disdain)
ZYGOMATICUS MINOR
ORIGIN * anterior aspect of zygomatic bone
INSERTION * skin of upper lip
ACTION * part of dilators of mouth * retract (elevate) or evert upper lip * deepen the nasolabial sulcus (sadness)
LEVATOR ANGULI ORIS
ORIGIN * infra-orbital maxilla
INSERTION * angle of mouth
ACTION * part of dilators of mouth * widens oral fissure (grinning or grimacing)
RISORIUS
ACTION * part of dilators of mouth * depresses labial commissure bilaterally to frown (sadness)
BUCCINATOR
ORIGIN * mandible * alveolar processes of maxilla and mandible * pterygomandibular raphe
INSERTION * angle of mouth * orbicularis oris
* thin, flat rectangular * more closely related to the buccal mucosa * fibers mingle medially with orbicularis oris
BUCCINATOR PLUS ORBICULARIS ORIS
ACTION
* presses cheeks against molar teeth * works with tongue to keep food between occlusal surfaces * resists distention when blowing
DEPRESSOR ANGULI
CRANIUM (SKULL) * skeleton of the head
2 Parts * Neurocranium * Viscerocranium
1. Neurocranium * cranial vault * bony case of the brain * has a dome like roof -calvaria or skullcap * has a floor or cranial base –Basicranium * these are irregular bones with flat portions * formed by a series of 8 bones * Frontal * Ethmoidal * Sphenoidal * Occipital * Temporal (2sets) * Parietal (2 sets)
2. Viscerocranium * facial skeleton * forms the anterior part of the cranium * consists of bones surrounding the orbits, nose and mouth * consists of 15 irregular bones * Mandible * Ethmoid * Vomer * Maxillae * Zygomatic * Palatine …show more content…
INSERTION * angle of mouth
ACTION * part of dilators of mouth * elevates labial commissure bilaterally to smile (happiness) * unilaterally to sneer (disdain)
ZYGOMATICUS MINOR
ORIGIN * anterior aspect of zygomatic bone
INSERTION * skin of upper lip
ACTION * part of dilators of mouth * retract (elevate) or evert upper lip * deepen the nasolabial sulcus (sadness)
LEVATOR ANGULI ORIS
ORIGIN * infra-orbital maxilla
INSERTION * angle of mouth
ACTION * part of dilators of mouth * widens oral fissure (grinning or grimacing)
RISORIUS
ACTION * part of dilators of mouth * depresses labial commissure bilaterally to frown (sadness)
BUCCINATOR
ORIGIN * mandible * alveolar processes of maxilla and mandible * pterygomandibular raphe
INSERTION * angle of mouth * orbicularis oris
* thin, flat rectangular * more closely related to the buccal mucosa * fibers mingle medially with orbicularis oris
BUCCINATOR PLUS ORBICULARIS ORIS
ACTION
* presses cheeks against molar teeth * works with tongue to keep food between occlusal surfaces * resists distention when blowing
DEPRESSOR ANGULI