Anterior and Posterior Views of the Skull: Key Structures and Landmarks

Skull Anatomy

Overview of the Skull

The human skull is a complex bony structure that forms the head and houses the brain, sensory organs, and the initial segments of the respiratory and digestive tracts. It is composed of several bones that are fused together in adults, providing protection and structural support.

• Cranial bones protect the brain and form the cranial cavity.

• Facial bones form the structure of the face, house the teeth, and provide attachment points for facial muscles.

Anterior View of the Skull

Major Bones and Landmarks

The anterior (front) view of the skull reveals several important bones and anatomical features. Understanding these structures is essential for identifying the relationships between different parts of the skull and their functions.

• Frontal bone: Forms the forehead and the superior part of the orbits (eye sockets).

• Parietal bone: Paired bones forming the superior and lateral aspects of the skull.

• Temporal bone: Located on the sides of the skull, containing structures of the ear.

• Sphenoid bone: A butterfly-shaped bone at the base of the skull, visible in the orbits.

• Ethmoid bone: Forms part of the nasal cavity and the medial wall of the orbits.

• Nasal bone: Small bones forming the bridge of the nose.

• Zygomatic bone: Cheekbones; form the prominence of the cheeks and part of the lateral wall of the orbits.

• Maxilla: Upper jawbone, forms part of the orbits, nasal cavity, and hard palate.

• Mandible: Lower jawbone; the only movable bone of the skull.

• Vomer: Forms part of the nasal septum.

Key Foramina and Fissures

Foramina (openings) and fissures (clefts) in the skull allow the passage of nerves and blood vessels.

• Supraorbital foramen: Opening above the orbit for the supraorbital nerve and vessels.

• Infraorbital foramen: Opening below the orbit for the infraorbital nerve and vessels.

• Optic canal: Passage for the optic nerve (cranial nerve II) and ophthalmic artery.

• Superior orbital fissure: Slit-like opening for cranial nerves III, IV, V1, and VI.

• Inferior orbital fissure: Passage for nerves and vessels between the orbit and the pterygopalatine fossa.

Other Notable Features

• Glabella: Smooth area between the eyebrows, above the nasal bones.

• Mandibular symphysis: Midline fusion point of the two halves of the mandible.

• Mental foramen: Openings on the anterior surface of the mandible for nerves and vessels.

• Inferior nasal concha: Curved bones projecting from the lateral walls of the nasal cavity.

• Perpendicular plate (of ethmoid): Forms the superior part of the nasal septum.

Table: Major Anterior Skull Structures and Their Functions

Structure	Location	Function/Significance
Frontal bone	Forehead, superior orbits	Protects frontal lobe, forms upper face
Maxilla	Upper jaw, below orbits	Houses upper teeth, forms part of nasal cavity and hard palate
Mandible	Lower jaw	Houses lower teeth, only movable skull bone
Supraorbital foramen	Above orbit	Passage for supraorbital nerve/vessels
Optic canal	Posterior orbit	Passage for optic nerve
Inferior nasal concha	Lateral wall of nasal cavity	Increases surface area for air filtration
Glabella	Between eyebrows	Landmark for facial measurements

Example: Clinical Relevance

• Fractures of the maxilla can affect the alignment of the teeth and the structure of the face.

• Injury to the infraorbital foramen may result in numbness of the upper lip and cheek due to nerve damage.

Additional info: The provided images and terms are from a standard anatomy and physiology textbook (Marieb, Human Anatomy & Physiology), and the structures listed are foundational for understanding craniofacial anatomy in health sciences.