The Skull - An Overview of Human Anatomy PDF

The Skull By: Dr. Rana Aldahlawi Function of the skull 01 02 03 04 Protects Provides Temporal Mandible the brain support to bone Movement of the lower jaw the face op...

The Skull By: Dr. Rana Aldahlawi Function of the skull 01 02 03 04 Protects Provides Temporal Mandible the brain support to bone Movement of the lower jaw the face opens and closes the mouth Surrounds the ears and allows chewing of food and protects nerves and structures that The lower set of teeth in the play role in mouth is rooted in the lower controlling hearing jaw and balance Skull consists of: 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 Maxillae 2 Zygomatic 2 Lacrimal 2 Nasal 2 Palatine 2 Inferior nasal conchae 1 Vomer 1 Mandible  SKULL VIEWS Anterior Aspect Lateral Aspect  SKULL VIEWS Inferior Aspect Superior Aspect  Frontal bone The frontal bone forms part of the roof of the orbital cavities, it contains two hollow spaces (sinuses) which 1 communicate with the nasal cavities. The frontal bones articulate with the parietal bones, sphenoid, zygomatic, 2 lacrimal, nasal and ethmoid bones. At birth the frontal bone consists of two parts separated by the 3 (frontal suture) but union is usually complete by the 8th year of life. Parietal bone 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 sagittal suture, and with the frontal bone at the coronal suture, and with the occipital bone at the lambdoid suture, and with the temporal bone at the squamous suture. Temporal bone Consists of: The squamous part, The mastoid part, which is external to the which contains lateral surface of the mastoid air cells temporal lobe of the brain The petrous part, The tympanic part, which encloses the which houses the internal and middle external auditory ears meatus and the tympanic cavity Ethmoid bone Facial bones Nasal bones Two small bones placed side by side between the frontal process of the maxillae and NEPTUNE form by their junction the Neptune is the eighth planet. bridge of the nose.  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 people and has both bony and cartilaginous elements. Inferior nasal conchae Zygomatic bone 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 NEPTUNE arch. Neptune is the eighth planet.  Maxilla bone Form the upper jaw, the two parts fused, and the lower part presents the alveolar process (contains sockets for NEPTUNE upper teeth) Neptune is the eighth planet. The maxilla contains the largest air sinus in the face: the maxillary sinus on each side which communicates with the nasal cavity  Mandible bone 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 TMJ the face and only movable bone of the skull. It articulates with the temporal bone to form TempoMandibular Joint (TMJ)  Palatine bone Two irregularly shaped bones posterior to the maxilla, contribute to the formation of the nasal cavity, the orbit, and the hard palate Frontal View Frontal Parietal Temporal Zygoma Vomer Nasal Maxilla Mandible Lateral View Frontal Lateral View Parietal Lateral View Temporal Mastoid Process (part of temporal bone) Lateral View Nasal Lateral View Zygoma Lateral View Maxilla  Lateral View Mandible TMJ Lateral View Sphenoid Lateral View Occipital External Auditory Meatus Superior View The base of the skull is formed mainly by 8 bones: Frontal bones Ethmoid bone Sphenoid bone 2 Temporal bones 2 Parietal bones Occipital bone Superior View Frontal Superior View Parietal  Superior View Temporal  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 It is a large opening in the Foramen occipital bone Magnum The spinal cord, an extension of the medulla oblongata, passes through the foramen magnum as it exits the cranial cavity. Sutures Sutures Are type of fibrous joint that are immovable and fuse completely around the age of 20 1 2 3 Coronal suture Sagittal suture Lambdoid suture Unites the frontal bone Unites the 2 parietal Unites the parietal bones with the parietal bones bones in the midline with the occipital bone 4 5 Squamosal suture Metopic suture Unites the squamous portion of the temporal (if present) unites the 2 bone with the parietal fontal bones bones  The junction of coronal and sagittal sutures is known as the bregma. The lambdoid and sagittal sutures join at a point known as the lambda.  Sutures in Fetal Skull The sutures of the fetal skull are soft fibrous tissues linking some bones of the skull. They enable expansion of the brain as it develops during childhood.  Skull Landmarks SKULL LANDMARKS SKULL LANDMARKS  Skull positioning lines 1 The Anthropological line The Isometric “Baseline” which runs from the inferior orbital margin to 1 the upper border of the external J auditory Meatus (EAM) 2 The Orbital- Meatal Line The original “Baseline” which runs from the Nasion through the outer Canthus of the eye to the center of 2 the external auditory Meatus.  Skull positioning lines 3 The Interpupillary line The line connects the centers of the orbits and is at 90 degree to the 3 median Sagittal plane. 4 The Auricular Line This line passes at 90 degrees to the anthropological line through the center of the external auditory meatus. 4  Summary 8 Cranial bones 1Frontal, 2 Parietal (R,L), Frontal view 1 Occipital, 2 Temporal (R,L), Lateral view 1 Sphenoid, 1 Ethmoid Superior view Skull Landmarks 2 4 6 1 32 5 7 14 Facial bones: Function of the Sutures: 2 Maxillae, 2 Zygomatic, Skull positioning skull Metopic, coronal, 2 Lacrimal, 2 Nasal, lines sagittal, lambdoid and 2 Palatine, 2 Inferior nasal conchae, squamosal 1 Vomer,1Mandible Sutures in fetal skull Thank you Any questions?