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

8 Cranial bones (cranium) Skull 8 Cranial bones (cranium) + 14 Facial bones

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

Facial bones (14) 2 Maxillary 2 Zygomatic 2 Lacrimal 2 Nasal 2 Palatine 2 Inferior nasal conche 1 Vomer 1 Mandible

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 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. Parietal

Frontal View 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. Temporal

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 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. Vomer

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 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. Maxilla

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 Sphenoid Nasal Zygoma Temporal Occipital Maxilla 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 Occipital The base of the skull is formed maily by 4 bones: (1) occipital bones, (2) Palatine bones, (3) Sphenoid bone, (4) Ethmoid bone.

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

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 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. 2 ( Note: there is a difference of 10 to 15 degrees between the Orbital- Meatal line and the anthropological line.) 2

Skull Landmarks The Interpupillary line 3 The Interpupillary line The line connects the centers of the orbits and is at 90 degree to the median Sagittal plane. 3 4 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 PA 0º PA axial 15º AP axial Lateral

Skull Series: Basic Projections PA axial 15º

Skull Series: Basic Projections AP axial

Skull Series: Basic Projections Lateral

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