Skull

•Parietals •Temporals Unpaired Cranial Bones: •Frontal •Occipital •Sphenoid •Ethmoid Paired Facial Bones: •Lacrimals •Nasals •Zygomatics •Maxillae •Palatines •Inferior Nasal Conchae Unpaired Facial Bones: •Vomer •Mandible •Hyoid

Lies in the ant.sup part of the skull •Supercilliary arch &super-orbital foramen •glebella

FRONTAL BONE

•Lies in the post.inf part of the skull •Foramen magnum

Esternal occipital protuberance Super&infer nuchal line

•Occipital condyl •Hypoglossal canal(12th cranial nerve immediately above the occipital condyl

Occipital bone

•Two parietal bone sup.later sides form roof of the cranium •External surface convex

PARIETAL BONE

IT CONSISTS FOUR PART: 1.CRISTA GALLI 2.PERPENDICULAR PLATE 3.CRIBIFORM PLAT 4.LABRYNTH:TWO LATERAL MASSES

ETHMOID BONE

•SITUATED MIDDLE OF THE BASE OF THE SKULL •BODY or central portion contain:sphenoid sinus •Leseer wings:ant.lateral •Greater wings:lateraly •Pterygoid process project donward from lateral sides of body or medial part of each greater wings

SPHENOID BONE (ant.view)

•Sella turcica; 1.Dorsum sellae •2Hypophyseal fossa •Tuberculum sellae

•Squamous part :flat and fine like project superiorly •Petrous part: three sided pyramid •Zygomatic process :projecy forward to face artidulate with temporal process of zygomatic bone

TEMPORAL BONE

•Steloid process: project downward •Glenoid fossa or mandibular fossa :for temporo-madibular joint •Mastoid process :atachment for sternocledomastoid muscle

•Form upper jaw •Frontal process;lateral margine of nose and articulate with frontal bone •Orbit plate:form floor of eye •Zygomatic process:articulat with zygomatic bone

MAXILLA

A Head Neck Coronoid process Condylar process

Mandibular notch Mandibular Foramen

Lingula

Alveolar Arch

Ramus

Mental protuberance

Angle Mental foramen

Body

•HORIZONTAL PART:inferior surface form post.part of hard plat &sup.surface form florr of nosal cavity •VERTICAL PART:form lateral side of nasla cavity

PLATINE BONE

•Frontal process:lateral margin of eye orbit and articulate with zygomatic process of frontal bone. •Temporal process:articulate withzygomatic process of temporal bone

Zygomatic bone

•Formbridge of the nose above the nasal cavity

NASAL BONE

•Articulate with perpendicular plat of ethmoid superirly

VOMER

•U SHAPED:located mid sagital plane infront of throat •Greater horns nad lesser hornes

HYOID BONE

Inferior nasal conchae

Frontal Bone

Coronal Suture

Glabella Parietal Bone

Supraorbital notch

Sphenoid Bone Lesser Wing

Orbital Surface

Greater Wing Nasal Bone Temporal Bone

Zygomatic Bone Frontal Process Orbital Process Temporal Process Zygomaticofacial foramen Maxilla Zygomatic Process Orbital Surface Infraorbital Foramen Frontal Process Alveolar Process Anterior Nasal Spine

Perpendicular Pplate Inferior nasal chonca Vomer Mandible Ramus Body Mental Foramen Mental Tubercle Mental Protuberance

Right Orbit : frontal and slightly lateral view

Orbital Surface of Frontal Bone

Orbital Surface of lesser wing of sphenoid bone Superior orbital Fissure Optic Canal Orbital Surface of greater wing of sphenoid bone

Posterior ethmodial foramania Anterior ethmodial foramania Orbital Plate of ethmoid bone lacrimal bone Fossa for lacrimal sac

Inferior orbital Fissure

Infraorbital groove

Orbital process of palatine bone

Orbital surface of maxilla

Greater wings of Sphenoid

Lacrimal bone

Maxilla

External Ecoustic Meatus Styloid process Zygomatic Bone

Greater Wings Lesser Wings

Squamous part Petrous Part

Optic Canal Sphenoid Sinus Frontal Sinus

Ethmoid Bone Crista Galli

Cribriform Plate

Jugular foramen Hypoglossal Canal

Perpendicular Plate

(Suture: Skull bone united at immobile joints. Suture Ligaments between the bone) Coronal Suture

Sagittal suture

FONTANELLE:unoss ified membrane intervals(6 in numb)

Bregma (meeting place of coronal and saggital suture) Lambda (meeting

Lambdoid suture

place of saggitaland lambdoid suture)

Cranial Base: Inferior View Maxilla Incisive fossa Palatine fossa Median palatine suture Zygomatic process Zygomatic Bone Frontal Bone External acoustic meatus Occipital condyle

Foramen ovale Foramen lacerum Foramen spinosum Hypoglossal canal Carotid canal

Condylar canal and fossa

•ANTERIOR CRANIAL FOSSA: formed by 1.orbital part of frontal bone 2.lesser wings 3.ant part of the body of sphenoid 4.cribiform plat 5.crista galli •MIDDLE CRANIAL FOSSA: formed by1.body of sphenoid 2.greater wings(deeply concave)3squamouse and petrous part of temporal bone,,,, ANTERIORLY BOUDED BY :POST BORDER OF LESSER WINGS AND ANT.CLINOID PROCESS AND ATERIOR MARGIN OF SULCUS PRECHIASMATICUS(optic groov) POSTERIORLY BOUNDED BY: sup border of petrous part of temporal bone and dorsum sellae •POSTERIOR CRANIAL FOSSA: largest and deepest,,formed by portions of the sphenoid,temporal,parietaland occipiotal bone

Frontal Bone Frontal crest Supr. Surface of orbital part Ethmoid bone Crista galli Cribriform plate Sphenoid bone Lesser wing Greater wing Body Temporal bone Squamous part Petrous part Parietal bone Occipitial bone Condyle Internal occipitial protuberance

Prechiasmatic groove Sella Turcica Tuberculum Sellae Hypophyseal fossa

Foramen cecum Post. Eth. foramen Optic Canal Sup. Orb. Fissure Foramen rotuntum

Dorsum sellae Posterior clinoid process Foramen ovale Foramen spinosum

Foramen lacerum Carotid canal Jugular foramen Condylar canal Hypoglossal canal

IMPORTANT OPENINGS IN THE BASE OF THE SKULL ANTERIOR CRANIAL FOSSA Perforation in cribiform plate----------ethmoid--------------olfactory nerve

MIDDLE CRANIAL FOSSA Optic canal-----------------lesser wing--------------------opyic nerve &opthalmic artery Sup.orbital fissure------bet.lesser and greater wings— 3rd (occulomoter)4rth(trochlear) 6th (abducent)5th (0pthalmic division) Foramen rotundum----greater wing-------5th (maxillary division of trigeminal nerve) Foramen oval------greater wings-----mandibular division of trigeminal nerve Foramen spinosum—greater wing-----------middle meningeal artery Foramen lacerum-----bet petrous part of temporal and sphenoid----inter carotid artery

POSTERIOR CRANIAL FOSSA Foramen magnum-----occipital---medulla oblongata and accery nerve Left vertebral artery

Hypoglossal canal---occipital----hypoglossal nerve Jugular foramen---bet petrous part of temporal and condylar part of occipital Glossopharyngeal (9th ),vagus(10th )accessory nerve(11th )

Inter accoustic meatus---petrous parth of temporal—vestibulocochlear(8th ) Facial(7th )