Skull anatomy: cranial nerves/ passageways/ landmarks

What is a foramen

An opening in bone that allows structures to pass through

What is a canal

A tunnel-like passage through bone

What is a fissure

A narrow slit-like opening in bone

What is a fossa

A depression or hollow area in bone

What is a process

A projection of bone

What is a meatus

A canal-like opening or passage

What is a condyle

A rounded articular surface that helps form a joint

What is the foramen magnum

A large opening in the occipital bone

What passes through the foramen magnum

CN XI (Accessory N.), vertebral arteries, anterior and posterior spinal arteries, inferior medulla and meninges

What is the external occipital protuberance

A bony projection on the posterior midline of the occipital bone

What is the mastoid process

A large rounded projection of the temporal bone

What is the styloid process

A thin pointed projection of the temporal bone

How can the mastoid and styloid processes be distinguished

Mastoid is thick and rounded, while styloid is thin and pointed

What is the mandibular fossa

A depression where the mandible articulates with the temporal bone

What joint involves the mandibular fossa

The temporomandibular joint

What is the external auditory meatus

The external opening leading into the ear canal

What are the occipital condyles

Rounded surfaces that articulate with the atlas

What vertebra articulates with the occipital condyles

C1 or the atlas

What is the carotid canal

A canal in the temporal bone

What is the foramen lacerum

An opening at the base of the skull

What passes through the cribriform plate

CN I (Olfactory N.)

What is the main function associated with CN I (Olfactory N.)

Smell

What is the crista galli

A vertical bony projection in the anterior cranial fossa

Where is the cribriform plate located

In the anterior cranial fossa around the crista galli

What is the cribriform plate

A perforated plate in the anterior cranial fossa

What is the anterior cranial fossa

The anterior depression of the internal skull base

What is the middle cranial fossa

The middle depression of the internal skull base

What is the posterior cranial fossa

The posterior depression of the internal skull base

What is the hypophysial fossa

A depression associated with the pituitary gland

What structure is associated with the hypophysial fossa

The pituitary gland

What passes through the foramen ovale

CN V (Trigeminal N. mandibular branch), lesser petrosal N., venous plexus

What passes through the foramen rotundum

CN V (Trigeminal N. maxillary branch)

What passes through the foramen spinosum

Meningeal branch of the mandibular N., middle meningeal artery, middle meningeal veins

What passes through the hypoglossal canal

CN XII (Hypoglossal N.), hypoglossal branch of the neuromeningeal trunk

What passes through the internal acoustic meatus

CN VII (Facial N.), CN VIII (Vestibulocochlear N.), intermediate N., labyrinthine artery and veins

What passes through the jugular foramen

CN IX (Glossopharyngeal N.), CN X (Vagus N.), CN XI (Accessory N.), meningeal branch of the occipital artery, internal jugular vein, inferior petrosal sinus

What passes through the optic canal

CN II (Optic N.), ophthalmic artery

What passes through the superior orbital fissure

CN III (Oculomotor N.), CN IV (Trochlear N.), CN V (Trigeminal N. ophthalmic branch), CN VI (Abducens N.), superior and inferior ophthalmic veins

What passes through the stylomastoid foramen

CN VII (Facial N.), stylomastoid artery and vein

Which trigeminal branch passes through the superior orbital fissure

Ophthalmic branch of CN V (Trigeminal N.)

Which trigeminal branch passes through the foramen rotundum

Maxillary branch of CN V (Trigeminal N.)

Which trigeminal branch passes through the foramen ovale

Mandibular branch of CN V (Trigeminal N.)

What is the trigeminal branch opening pattern

Ophthalmic through superior orbital fissure, maxillary through foramen rotundum, and mandibular through foramen ovale

Which cranial nerves pass through the internal acoustic meatus

CN VII (Facial N.) and CN VIII (Vestibulocochlear N.)

Which cranial nerves pass through the jugular foramen

CN IX (Glossopharyngeal N.), CN X (Vagus N.), and CN XI (Accessory N.)

Which opening carries CN XII (Hypoglossal N.)

Hypoglossal canal

Which opening carries CN II (Optic N.)

Optic canal

Which opening carries CN I (Olfactory N.)

Cribriform plate

Which opening carries CN VII (Facial N.)

Stylomastoid foramen

What is CN I called

Olfactory N.

What is CN II called

Optic N.

What is CN III called

Oculomotor N.

What is CN IV called

Trochlear N.

What is CN V called

Trigeminal N.

What is CN VI called

Abducens N.

What is CN VII called

Facial N.

What is CN VIII called

Vestibulocochlear N.

What is CN IX called

Glossopharyngeal N.

What is CN X called

Vagus N.

What is CN XI called

Accessory N.

What is CN XII called

Hypoglossal N.