Terms

• Cranium

The cranium comprises all of the bones of the skull except for

the mandible.

• Skull

The skull refers to all of the bones that comprise the head.

• Calvaria

The calvaria refers to the cranium without the facial bones

attached.

• Splanchocranium

The splanchocranium refers to the facial bones of the skull.

• Neurocranium

The neurocranium refers only to the braincase of the skull.

• Suture

The saw-like edge of a cranial bone that serves as joint between

bones of the skull.

Neurocranium

Paired Cranial Bones:

Parietal

Temporal

Unpaired Cranial Bones:

Frontal
Occipital
Sphenoid
Ethmoid

Neurocranium, comprising membranous and cartilaginous
portions; the former, the calvaria, includes the frontal and
parietal and portions of the temporal, occipital, and
sphenoid bones; the latter, the chondrocranium, includes the
ethmoid and portions of the occipital, temporal, and
sphenoid bones.

Splanchnocranium

Paired Facial

Bones:
Lacrimal
Nasal
Zygomatic
Maxilla
Palatine
Inferior Nasal
Concha

Unpaired Facial

Bones:
Vomer
Mandible
Hyoid

Growth of the neurocranium is

directly related to expansion

of the brain.
The bones of the

neurocranium are joined by

fibrous sutures, which permit

growth at the edges of the

bone. The sutures are

relatively wide at birth, with

large gaps where two or more

sutures meet. These areas are

called fontanelles, and include

the anterior fontanelle, often

refered to as a baby’s "soft

spot." Even after visible gaps

between the neurocranial

bones have closed, the

fibrous suture permits

additional growth to occur.

Eventually, the bones at that

suture fuse together. The

metopic suture normally fuses

relatively early (anywhere

from 3 to 7 years), although

the other neurocranial sutures

remain patent into adulthood.

SUTURES

1.Coronal- between parietal & frontal
2.Sagittal- between right and left parietal

bones

3.Lambdoid- between parietal & occipital
4.Squamous – between parietal &

temporal

Frontal bone

Parietal bone

Occipital bone

Orbit

• Provides

protection
to the
globe

• A pyramid

in shape
with apex
at foramen

ORBIT

• Boundaries

– Superior : orbital plate

of Frontal bone and
small part of Lesser
Wing of the sphenoid

– Lateral : Greater wing

of the sphenoid and
frontal process of the
Zygomatic bone

– Medial : Orbital lamina

of the ethmoid bone
and lacrimal bones.

– Inferior : Maxillary

bone

FORAMINA

INFERIOR ORBITAL FISSURE:

Carries the Maxillary Nerve (V2)

INFRAORBITAL FORAMEN

: in the orbital part of

the maxillary bone.

• It transmits the Infraorbital Nerve (V2) out of the orbit.

• It transmits the Infraorbital Artery -- an anastomotic

branch between the Angular and Maxillary Aa. (both of

which are off the External Carotid).

ETHMOID FORAMEN

: Anterior and posterior

foramina in the medial wall, transmitting structures

that are

going from orbit to the ethmoid air sinuses and nose:

• Anterior and Posterior Ethmoid Arteries, from

Opthalmic Artery

• Anterior and Posterior Ethmoid Nerves, from

Nasociliary Nerve (V1)

SUPERIOR ORBITAL FISSURE:

Between the lesser and greater

wings of the sphenoid bone.

It transmits the Superior Ophthalmic Vein.
It transmits: Oculomotor (III), Trochlear (IV), Opthalmic (V1), and
Abducens (VI)

OPTIC CANAL

: In the Lesser Wing of Sphenoid, superomedial to the

superior orbital fissure.

It transmits the Optic Nerve (II)
It transmits the Ophthalmic Artery, a branch from the Internal
Carotid.

TEMPORAL FOSSA

Boundaries:
• Temporal lines
• Zygomatic arch
Connections:
• Infratemporal

fossa

Contents:
• Temporalis

muscle

• Deep temporal

vessels and

nerves

INFRATEMPORAL FOSSA

BOUNDARIES

• RAMUS OF THE MANDIBLE laterally,

• LATERAL PTERYGOID PLATE medially,

• TUBEROSITY OF THE MAXILLA anteriorly,

• CRANIAL BASE (greater wing of the sphenoid bone) superiorly.

• STYLOID PROCESS posteriorly

• The MEDIAL PTERYGOID MUSCLE bounds the fossa inferiorly

Infratemporal fossa-

connections

• The foramen ovale and foramen

spinosum open on its roof, and the
alveolar canals on its anterior wall.

• At its upper and medial part are two

fissures, which together form a T-
shaped fissure, the horizontal limb
being named the inferior orbital, and
the vertical one the pterygomaxillary.

Infratemporal fossa-

contents:

MEDIAL PTERYGOID MUSCLE
MAXILLARY ARTERY AND VEIN,
PTERYGOID PLEXUS OF VEINS,
MANDIBULAR DIVISION OF CN-V
OTIC GANGLION.

PTERYGOPALATINE FOSSA

Boundaries
Posterior:

• - root of the pterygoid plates

• - inferior surface of the greater

wing of the sphenoid bone

Anterior:

• - posterior surface of the maxilla
Superior:

• - posterior part of the inferior

orbital fissure

• - orbital process of the palatine

bone

• -body of the sphenoid bone
Inferior:

• -apex leading in to the

pterygopalatine canal

Medial:

• - perpendicular plate of the

palatine bone

Lateral:

• - location of the pterygomaxillary

fissure

a-inferior orbital fissure
b-posterior surface of the maxilla
c-pterygo-maxillary fissure (leads
to the pterygo-palatine fossa)

Contents:

Maxillary nerve V2 (second division of

the Trigeminal nerve),

Pterygopalatine ganglion
The third part of the Maxillary artery

• .

Ethmoid bone

Sphenoid bone

Temporal bone