Chapter 6 Bones
THE SKULL
The Skull
 Contains 22 bones
 8 Cranial Bones
 Provides protection of the brain
 Stabilizes brain, blood vessels and nerves
 Outer surface provides sights for muscle
attachment
 14 Facial Bones
 Form framework of face
 Protect and provide support for the entrances of
the respiratory and digestive system
 Provide muscle attachment for muscles involved
in facial expressions
Cranial Bones
 Frontal Bone
 Forms the
forehead
 Roof of the orbits
 Contains the
frontal sinuses
 Act as sound
chambers that
give voice
resonance
Cranial Bones
 Parietal Bones
 2 bones
 Form most of the sides and
roof of the cranial cavity
Cranial Bones
 Temporal Bone
 2 Bones
 Forms the lower side of the cranium and part of the
cranial floor
 Temporal and Zygomatic bone join to make the
Zygomatic Arch
 Mandibular fossa forms a joint with the condylar process
of the mandible to form the Temporomandibular Joint
(TMJ)
 External Auditory Meatus: canal which leads to the
middle ear
 Mastoid Process: round projection of the temporal bone;
point of attachment for neck muscles
Cranial Bones
 Temporal Bone
Continued
 Styloid Process: Projection,
points downward from
under the temporal bone.
 Serves as point of
attachment for muscles
and ligaments of the
tongue and neck
 Carotid Process: hole
through which the carotid
artery passes
Cranial Bones
 Occipital Bone
 Forms the posterior portion of the skull and
most of the cranium
 Foramen Magnum: largest foramen(hole) in
the skull
 Contains the Medulla oblongata,
connecting to the spinal cord
 Occipital Condyles: oval processes on each
side of the Foramen
 Connects with the cervical vertebra
Cranial Bones
 Occipital Bone
Cranial Bones
 Occipital Bone
 Forms the posterior portion of the skull and
most of the cranium
 Foramen Magnum: largest foramen(hole) in
the skull
 Contains the Medulla oblongata,
connecting to the spinal cord
 Occipital Condyles: oval processes on each
side of the Foramen
 Connects with the cervical vertebra
Cranial Bones
 Sphenoid Bone
 Lies at the middle part of the base of the school
 “Keystone” of cranial floor-articulates(connects)
with all of the cranial bones, holding them
together
 Resembles a bat with out stretched wings
 Hypophyseal fossa: depression in sphenoid bone
contains the pituitary gland
Cranial Bones
 Sphenoid Bone
Cranial Bones
 Ethmoid Bone
 Found in the anterior part of the cranial floor
between the orbits
 Forms the anterior portion of the cranial floor,
the medial wall of the orbits, the superior
portions of the nasal septum.
 Nasal Septum: divides the nasal cavity into left
and right sides
 Cribriform Plate: forms the roof of the nasal
cavity
Cranial Bones
 Ethmoid Bone
Facial Bones
 Nasal Bones (2)
 Form part of the bridge of the nose
Facial Bones
 Maxillae Bones (2)
 Singular is maxilla
 The maxilla join together to form the upper
jawbone
 Forms the anterior 3/4th the hard palate
Facial Bones
 Palatine Bones
(2)
 Fused Lshaped bones
 Form the
posterior
portion of the
hard palate
 Cleft Palate:
incompletely
fused palatine
bones
Facial Bones
 Mandible
 Lower Jawbone
 Largest, strongest
facial bone
 Condylar Process:
articulates with the
mandibular fossa of
temporal bone;
forms the
temporomandibular
joint
Facial Bones
 Zygomatic bones (2)
 Cheekbones
 Lacrimal bones (2)
 Smallest bones in the face
 Inferior Nasal Conchae (2)
 Filter air before it passes through the lungs
 Vomer
 Triangular bone
 Helps form the nasal septum
Facial Bones
 Zygomatic bones (2)
 Cheekbones
 Lacrimal bones (2)
 Smallest bones in the face
Facial Bones
 Inferior Nasal
Conchae (2)
 Filter air before
it passes
through the
lungs
 Vomer
 Triangular
bone
 Helps form the
nasal septum
Unique Skull Features
 Suture: immovable joints only found in the skull of
an adult.
 Coronal Suture: unites the frontal bone and 2
parietal bones
Unique Skull Features
 Sagittal Suture: unites the 2 parietal bones
Unique Skull Features
 Lamboid Suture: unites the parietal bones with
the occipital bone
Unique Skull Features
 Squamous Suture: unites the parietal bones with
the temporal bone
Unique Skull Features
 Paranasal Sinuses:
paired cavities
 Located in certain
skull bones near the
nasal cavity
 Produce mucus
 Serve as resonating
chambers; allow you
to produce unique
sounds
 Lighten the skull