Human Anatomy: Skull and Muscles of Mastication

Skull Views

• Norma Frontalis: Anterior view of the skull
• Norma Verticalis: Superior view of the skull
• Norma Occipitalis: Posterior view of the skull
• Norma Basalis: Inferior view of the skull

Mandible and Muscles of Mastication

• Mandible: Lower jawbone
• Temporal and Infratemporal Fossa: Bony cavities in the skull

Muscles of Mastication

• Temporalis • Origin: Floor of temporal fossa and deep surface of temporal fascia • Insertion: Coronoid process and anterior border of ramus mandible • Nerve Supply: Anterior division of mandibular nerve • Action: Elevation of mandible by anterior fibers and retraction by posterior fibers
• Masseter • Origin: Lower border and inner surface of zygomatic arch • Insertion: Lateral surface of ramus of mandible • Nerve Supply: Anterior division of mandibular nerve • Action: Elevation and protraction of mandible
• Lateral Pterygoid • Origin: Upper head from infratemporal surface of greater wing of sphenoid bone, lower head from lateral surface of lateral pterygoid plate • Insertion: Anterior aspect of neck of mandible and articular disc of temporo-mandibular joint • Nerve Supply: Anterior division of mandibular nerve • Action: Depression of mandible (opening the mouth) and protraction of mandible

Important Notes

• All muscles of mastication take origin from the skull and are inserted in the mandible
• All muscles receive nerve supply from the mandibular nerve
• All muscles elevate the mandible (close the mouth) except lateral pterygoid, which depresses the mandible (open the mouth)
• All muscles protract the mandible except temporalis, which retracts the mandible
• Medial and Lateral Pterygoid muscles move the mandible side to side (chewing)

This quiz covers the anatomy of the skull, including the norma frontal, vertical, occipital, and basalis views, as well as the muscles of mastication, including temporal, masseter, lateral pterygoid, and medial pterygoid.