2. The skull
• is composed of 28 separate bones .
• Many of the bones are flat bones
The inner table is thinner and
more brittle.
The outer table is generally very
resilient.
3. …cont
• The skull bones vary in thickness in different
regions, but tend to be thinner where they are
covered by muscles, for example in the
temporal and posterior cranial fossae.
• The bone is thinner in women and children
when compared with adult males.
4. Function
• Cranial bones
– Enclose and protect the brain
– Provide attachment for head and neck muscles
• Facial bones
– Form framework of face
– Form cavities for sense organs (sight, taste, smell)
– Provide passage for air/food
– Hold the teeth
5. The cranium (skull) is the skeleton of the head
A series of bones form its two parts,
1-cranial vault is the bony covering (case) of the brain ,
cranial nerves and the vasculature of the brain.
2-facial bones
7. The CRANIAL has a calvaria (skullcap), and a
floor or cranial base (basicranium).
The CRANIAL in adults is formed by a series of
eight bones:
four singular bones centered on the midline
(frontal, ethmoidal, sphenoidal, and occipital)
and two sets of bones occurring as bilateral pairs
(temporal and parietal)
8. 2-The viscerocranium (facial skeleton)
comprises the facial bones
The viscerocranium forms the anterior part of
the cranium and consists of the bones
surrounding the mouth (upper and lower jaws)
nose/nasal cavity,
and the orbits (eye sockets or orbital cavities).
10. It consists of 15 irregular bones:
three singular bones centered on or lying in
the midline (mandible, ethmoid, and vomer)
and 6 bones occurring as bilateral pairs
(maxillae; inferior nasal conchae; and
zygomatic, palatine, nasal, and lacrimal
bones)
11. The maxillae and mandible house the teeth
that is, they provide the sockets and
supporting bone for the maxillary and
mandibular teeth.
The maxillae contribute the greatest part of
the upper facial skeleton, forming the
skeleton of the upper jaw, which is fixed to
the cranial base.
19. The Fetal Skull
Fontanelles – fibrous membranes connecting the
cranial bones
Convert to bone within 24 months after birth
They Allow:-
1- the brain to grow
2-allow movement of the bones to enable the skull
to pass through the birth canal
27. M
P
S
T
V
O
INCISIVE CANAL
PALATINE PROCESS
OF MAXILLA
HORIZONTAL PROCESS
OF PALATINE BONE
CHOANA
GREATER WING
PTERYGOID
PROCESS
BODY OF SPHENOID
FORAMEN LACERUM
FORAMEN OVALE
FORAMEN SPINOSUM
MANDIBULAR
FOSSA
STYLOID
PROCESS
EXTERNAL
AUDITORY
MEATUS
MASTOID
PROCESS
FORAMEN MAGNUM
INF. NUCHAL LINE
SUP. NUCHAL LINE
Carotid canal
32. F
P
O
T
S
RADIOGRAPHIC AND CRANIOMETRIC LANDMARKS
Bregma
Lambda
Inion
Glabella
Nasion
Ant. Nasal
spine
Menton
Pterion(WEAKEST part)
VERTEX (highest point)
Z
Max
Mand
33.
34. • The mandible forms the skeleton of the lower
jaw, which is movable because it articulates
with the cranial base at the
temporomandibular joints (TMJs
35. Hyoid Bone
• Suspended in mid-neck region (not
attached directly to bones)
– 1 inch above larynx
– Horseshoe-shaped
• Movable base for tongue and allow
neck muscles to attach and move
larynx up and down
36. Paranasal Sinuses
Hollow portions of bones surrounding the nasal cavity
Functions of paranasal sinuses:
Lighten the skull
Give resonance and amplification to voice
37. Muscles of the skull:
• Epicranial
• Temporalis
• Oricularis oculi
• Occibitifrontalis
• Nasalis
