Head and neck

Neurocranium

Surrounds and protects the brain

Bones of the neurocranium

Frontal
Parietal
Sphenoid
Occipital
Temporal
Ethmoid

Viscerocranium

Forms the framework of the face and contributes to the nasal and oral cavities and the orbits

Bones of the viscerocranium

Mandible
Maxillae
Nasal Bone
Vomer
Zygomatic bone
Lacrimal bone
Palatine bone
Hyoid bone

Both neurocranium and viscerocranium

Frontal bone

Sphenoid bone

Ethmoid bone

Temporal bone

Maxillae and palatine bones

Sutures

a fibrous joint found between most bones of the skull. Joined together by a thin layer of dense fibrous connective tissue (sutural ligament). Functional classified as synarthroses permitting little or no movement. Functional significance is to provide a strong light weight protective case around the brain

Temporomandibular joint articular surfaces, histological classification, functional classification and movements

Articular surface: head of mandibular condyle and mandibular fossa and articular tubercle of the temporal bone

Histological classification: synovial joint

Functional classification: modified hinge and gliding

Movements: elevation, depression, protraction, retraction, lateral deviation

Paranasal sinuses what, communicate, lies

What: air filled cavities within bones surrounding the nasal cavity

Communicate: with the nasal cavity through small openings

Lie:

• superior to the nasal cavity in the frontal lobe

• lateral and inferior to it in the maxillae

• posterior and superior to it in the sphenoid

Oral cavity what, divisions and relationships

what: extends from the lips to the oropharynx

divisions:

• the oral vestibule, between the lips/cheeks and teeth

• the oral cavity proper, medial to the teeth

relationship:

• inferior to the nasal cavity

• separated from it by the head and soft palates

• anterior to the oropharynx

• communicates posteriorly with the oropharynx through the oropharyngeal isthmus

Cranial dura matter

Endosteal layer: adheres to the inner surface of the skull and acts as its internal periosteum

Meningeal layer: lies deep to the endosteal layer and continues through the foramen magnum as spinal dura

The layers are normally fused. they seperate to form dural venous sinuses where the meningeal layer folds inwards to form dural partitions

Falx cerebri

is a vertical, sickle shaped fold between the cerebral hemispheres

attachments:

• anteriorly: crista galli and frontal crest

• superiorly: internal surface of cranial vault

• posteriorly: blends with the tentorium cerebelli

• inferior border: free above the corpus callosum

Function: separates the cerebral hemispheres

Tentorium cerebelli

The tentorium cerebelli is a horizontal, tent-shaped dural fold between the occipital lobes superiorly and the cerebellum inferiorly

Attachments:

• posterior clinoid process

• superior borders of the petrous temporal bones

• occipital bone along the transverse sinus grooves

Function: supports the occipital lobes and separates the cerebrum from the cerebellum

Middle cranial fossa boundaries

Anterior: Lesser wing of sphenoid
Posterior: Petrous part of temporal bone
Medial: Body of sphenoid
Lateral: Temporal and parietal bones

Temporal fossa boundaries

Superior: temporal lines
Anterior: frontal and zygomatic bones
Inferior: Zygomatic arch

Optical canal location, communication and content

L: sphenoid
Com: Middle cranial fossa to orbit
Con: CNII (optic nerve)

Jugular foramen location, communication and contents

L: between patrols part of temporal bone and occipital bone
Com: Posterior cranial fossa and the neck
Con: Internal Jugular vein, CNs IX, X, and XI (glossopharyngeal, vagus, and accessory nerves)

Foramen Ovale location, communication, and contents

L: greater wing of sphenoid
Com: Middle cranial fossa and infra temporal fossa
Con: CN V3 (Mandibular branch of trigeminal nerve)

Foramen Spinosum Location, communication and contents

L: greater wing of sphenoid
Com: middle cranial fossa and infra temporal fossa
Con: middle meningeal artery

Foramen rotundum location, communication and contents

L: greater wing of sphenoid
Com: middle cranial fossa and pterygopalatine fossa
Con: maxillary branch of trigeminal nerve

Internal auditory meatus location, communication and contents

L: Petrous part of temporal bone
Com: posterior cranial fossa and tympanic cavity
Con: Facial nerve (CN VII) and vestibulochochlear nerve (CN VIII)

Carotid canal location and contents

L: petrous part of temporal bone
C: internal carotid artery

Superior orbital fissure location and contents

L: between lesser and greater wings of sphenoid
Con: Occulomotor (CN III), abducent (VI), and torchlear (IV) CNs, ophthalmic branch of trigeminal nerve

Flax cerebi attachments and function

Anterior: Cristal Gali (part of ethmoid bone)
Posterior: fuses with superior surface of tentorium cerebelli
Function: separates two cerebral hemispheres

Tentorium cerebelli attachments and function

Anterolaterally: petrous part of temporal bone
Posterior: transverse sulcus of occipital bone
Function: forms roof over posterior cranial fossa -> 'tent' over cerebellum

Meninges layers (superficial to deep)

Duramater
Arachnoid mater (avascular)
Pia mater (attached to surface of brain)

Functions of paranasal sinuses

Assist with sound resonation
Reduce weight of skull
Humidify inhaled air