Radiographic Anatomy
Skeletal System
Skull
Educational Objectives
By the end of this lecture you should be able to:

Identify the anatomical parts of skull on diagrams and
radiographs.

Identify the different sutures of the skull
State the surface land marks of skull and explain its
importance in radiographic positioning
Explain how to hang skull radiographs on the view box


References
1. Text book of radiographic positioning and related anatomy; by
Kenneth L.Bontrager,6th edition.
2. Introduction to Human Anatomy and Physiology: by Eldra
Pearl Solomon:W.B.Saunders Company
3. Handbook of Anatomy and physiology for Students of Medical
Radiation Technology: Mallett.M:Jaspar
Websites
http://www6.district125.k12.il.us/science/anatomy/
http://www.innerbody.com/htm/body.html
http://www.e-radiography.net/
http://www.getbodysmart.com/index.htm
4
Skull
8 Cranial bones (cranium)
+
14 Facial bones
5
Cranial bones (8)
 Skull Cap (Calvarium):
● 1 Frontal
● 2 Parietal (R,L)
● 1 Occipital
 Skull Base (floor):
● 2 Temporal (R,L)
● 1 Sphenoid
● 1 Ethmoid
6
Facial bones (14)
• 2 Maxillary
• 2 Zygomatic
• 2 Lacrimal
• 2 Nasal
• 2 Palatine
• 2 Inferior nasal conche
• 1 Vomer
• 1 Mandible
7
Skull views
Lateral Aspect
Anterior Aspect
Skull views
Superior Aspect
Inferior Aspect
Frontal View
The frontal bone forms
part of the roof of the
orbital cavities, it
contains two hollow
spaces (sinuses) which
communicate with the
nasal cavities. The
frontal bones articulate
with the parietal bones,
sphenoid, zygomatic,
lacrimal, nasal and
ethmoid bones. At birth
the frontal bone
consists of two parts
separated by the
(frontal suture) but
union is usually
complete by the 8th year
of life.
Frontal
Frontal View
Parietal
Two bones form the
sides of the vault just
behind the frontal
bone on each side of
the median plane.
They articulate with
each other at the
sagital suture, with the
frontal bone at the
coronal suture, with
the occipital bone at
the lambdoid suture,
and with the temporal
bone at the squamous
suture.
Frontal View
Temporal
These two bones lie on each side
of the head below the parietal
bones; each one is divided into
five parts: (1) Squamous part, (2)
Mastoid process: can be felt
behind the ear , contains large
number of air sinuses which
become areated only in adults.(3)
Tympanic part : in front of the
mastoid and below the squamous,
form part of the osseous part of
EAM. (4) Styloid process, (5)
Petrous part of temporal bone:
forms part of the base of the skull
,contains organs of hearing and
equilibrium and IAM. Which
transmits the facial nerve and
vestibulocochlear nerve. It
contains also the carotid canal
which trasmits ICA. And the
jugular foramen which transmits
the IJV.
Frontal View
Two small bones
placed side by side
between the frontal
process of the
maxillae and form by
their junction the
bridge of the nose.
Nasal
Frontal View
Vomer
Form part of the
nasal septum
together with the
perpendicular plate
of the ethmoid bone
and articulate with
the nasal bones.
The nasal septum is
often deviated to
one side in most of
the people and has
both bony and
cartilagenous
element.
Frontal View
Form the
prominence of the
cheek and part of the
lateral walls of the
orbit and articulate
with the temporal
bone to form the
zygomatic arch.
Zygoma
Frontal View
Maxilla
Form the upper jaw,
the two parts
together, the lower
part present the
alveolar process
(contains sockets for
upper teeth) the
maxillae contain the
largest air sinus in
the face : maxillary
sinus on each side
which communicates
with the nasal cavity.
Form the lower jaw, it is
composed of two bodies
united at the symphysis
menti, two rami project
upwards from the
posterior part of the body,
the point of junction is the
angle of the jaw. The
mandible is the strongest
bone of the face and only
movable bone of the
skull. It articulates with
the temporal bone to form
TMJ
Mandible
Frontal View
Frontal
Parietal
Temporal
Zygoma
Vomer
Nasal
Maxilla
Mandible
Frontal View
Lateral View
Lateral View
Frontal
Lateral View
Parietal
Lateral View
Temporal
Lateral View
Nasal
Lateral View
Zygoma
Lateral View
Maxilla
Lateral View
Mandible
Lateral View
The sella turcica
present a saddle –
shaped depression
lying on the
superior surface of
the middle part of
the sphenoid bone.
It supports the
pituitary gland. The
parts of the sella
turcica are: (1)
Anterior clinoid
processes, (2)
Dorsum sellae =
posterior clinoid
processes, (3)
Lamina dura which
cover the floor of
sella, (4) Sphenoid
air sinuses.
Sphenoid
Lateral View
Occipital
Lateral View
Mastoid Process
(part from temporal bone)
Lateral View
External Auditory Meatus
Lateral View
Frontal
Parietal
Nasal
Sphenoid
Zygoma
Temporal
Maxilla
Occipital
Mandible
Mastoid Process
Lateral View
Superior View
Frontal
Superior View
Parietal
Superior View
Temporal
Superior View
Vomer
Superior View
Sphenoid
Superior View
Forms the back of
the head , its inner
surface is concave
and contains the
occipital lobes of
the brain and the
cerebellum, it forms
part of the base of
the skull.
Occipital
Superior View
Foramen Magnum
Superior View
Frontal
Vomer
Sphenoid
Parietal
Temporal
Foramen
Magnum
The base of the
skull is formed
maily by 4 bones:
(1) occipital bones,
(2) Palatine bones,
(3) Sphenoid bone,
(4) Ethmoid bone.
Occipital
Sutures
Sutures
Sagittal
Sutures
Frontal
(Coronal)
Sutures
Squamous
Sutures
Lambdoid
Sutures
Sagittal
Frontal
(Coronal)
Squamous
Lambdoid
Sutures
Frontal
Sagittal
Lambdoid
Superior Aspect
Skull Landmarks
1.Vertex
2. External Occipital Protuberance (E.O.P.)
3. External Auditory Meatus
4. Outer Canthus Of Eye.
5. Infra-orbital point
6. Nasion
7. Glabella
49
Skull positioning lines
1
The Anthropological line
The Isometric “Baseline” which runs from the
inferior orbital margin to the upper border of
the external auditory Meatus (EAM)
1
2
The Orbital- Meatal Line
The original “Baseline” which runs from the
Nasion through the outer Canthus of the
eye to the centre of the external auditory
Meatus.
( Note: there is a difference of 10 to
15 degrees between the OrbitalMeatal line and the anthropological
line.)
2
Skull Landmarks
3
4
The Interpupillary line
The line connects the centers of the orbits
and is at 90 degree to the median Sagittal
plane.
3
The Auricular Line
This line passes at 90 degrees to the
anthropological line through the centre of
the external auditory meatus.
4
Skull Landmarks
Skull Landmarks
Cranial Topography

Glabella: raised triangular area bet. eyebrows.

Nasion: depression at the bridge of the nose.

Acanthion: nose and upper lip meet

Tragus: cartilage. flap covering ear opening.

Top of ear attachment (TEA): side frames of eyeglass rest
(level of petrous ridge).

Gonion: angle of mandible.

Inion: prominent point of EOP.
Skull Series: Basic Projections
1.
PA 0º
2.
PA axial 15º
3.
AP axial
4.
Lateral
Skull Series: Basic Projections
PA axial 15º
Skull Series: Basic Projections
AP axial
Skull Series: Basic Projections
Lateral
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