Skull Lesson 5: Facial Bone Anatomy Flashcards

Facial Bone Anatomy

• Total Facial Bones: 14, including pairs: Nasal (2), Lacrimal (2), Maxilla (2), Zygomatic (2), Palatine (2), Inferior Nasal Conchae (2), Vomer (1), Mandible (1).
• Unpaired Facial Bones: Vomer and Mandible are the only non-paired bones.

Maxillary Bones

• Largest Immovable Facial Bone: Articulates with all facial bones except the mandible, contributing to the orbital cavity walls.
• Acanthion: The junction of right and left maxillary bones forms the anterior nasal spine.
• Articulations: Connect with the Oral, Nasal, and Two Orbits cavities.
• Processes: Each half has four processes: Frontal, Zygomatic, Palatine, and Aveolar.
• Aveolar Processes: Support the roots of upper teeth.
• Zygomatic Processes: Extend laterally to join the zygomatic bone.

Palatine Bones

• Structure: Forms the posterior quarter of the roof of the mouth; consists of horizontal and vertical portions.
• Horizontal Portion: Articulates posteriorly with the maxillary bones.
• Vertical Portion: Projects upward to form the posterior aspect of the medial orbits.

Zygomatic Bones

• Location: Forms the lateral aspect and floor of the orbits, articulating with multiple bones including the frontal and temporal bones.
• Composition: Formed by the union of zygoma and temporal bone, with the temporal process extending to unite with the zygomatic process.

Nasal Bones

• Characteristics: The thinnest, most fragile bones, articulating with the perpendicular plate of the ethmoid bone and maxilla.

Lacrimal Bones

• Size: Smallest bones of the skull, situated between the ethmoid and maxilla, forming part of the medial orbit wall.

Inferior Nasal Conchae

• Shape: Long, narrow, and scroll-shaped, curving laterally.
• Function: Covered in mucous membrane for air warming, moistening, and cleaning.

Vomer Bone

• Structure: A thin plate that makes up the inferior nasal septum, located at the mid-sagittal plane, forming the nasal cavity floor.

Hyoid Bone

• Shape: "U" shaped, serves as an attachment point for the larynx and tongue muscles, and is unique as it does not articulate with any other bone.

Cavities Formed by Facial Bones

• Cavities: Include the Oral Cavity, Nasal Cavity, and Orbits.

Orbits

• Shape: Cone-shaped, housing organs, nerves, and blood vessels associated with sight.
• Orientation: Project 30 degrees superiorly from OML and 37 degrees medially to MSP.
• Apex: Most posterior part of the orbits, terminating at the optic foramen.
• Bone Composition: Comprised of 7 bones total: 3 cranial (Frontal, Sphenoid, Ethmoid) and 4 facial (Maxilla, Zygoma, Lacrimal, Palatine).

Orbital Openings and Fractures

• Posterior Openings: Include Optic Foramen, Sphenoid Strut, Superior Orbital Fissure, and Inferior Orbital Fissure.
• Common Orbital Fractures: Blow Out Fractures typically from direct hits, mainly affecting the orbital floor; Tri-Pod Fractures involving separation of zygoma's three major attachments.

Delve into the anatomy of the facial bones with these flashcards designed for Lesson 5 on skull structures. Test your knowledge on the number of facial bones, their characteristics, and identifying the unique features of each bone. Perfect for students and enthusiasts of human anatomy.