IN THE NAME OF ALLAH

The Skull 5

Interior of the skull

Inferior aspect of the skull cap a Sutures Frontal crest Vascular grooves for branches of the middle meningeal artery Granular Foveolae- pits formed by arachnoid granulations (site of CSF transfer) Groove for the superior sagittal sinus-large venous channel within the dura mater Diploe- cancellous bone containing red marrow Groove for superior sagittal sinus Grooves for middle meningeal artery Diploe Granular foveolae

Cranial Base Internal part of the cranial base is divided into three major regions or fossae: Anterior cranial fossa Middle cranial fossa Posterior cranial fossa These three fossae lie at different levels Anterior cranial fossa Middle cranial fossa Posterior cranial fossa

Anterior Cranial Fossa Ethmoid Fossa is formed by the: Orbital part of the frontal bone Ethmoid bone in the middle Body and Lesser wing of the sphenoid Orbital portion of the frontal bone Lesser wing of the sphenoid

Anterior Cranial Fossa Frontal crest- a median bony extension from the frontal bone Foramen cecum is located at the base of the crest Crista galli- ridge of bone projecting superiorly from the ethmoid bone and serves as the attachment for the cerebral falx Sphenoid (jugum) Frontal crest Crista galli Foramen cecum

Anterior Cranial Fossa Cribriform plate for passage of the olfactory axons into the cranial cavity Optic canal for passage of the optic nerve (CN II) and the ophthalmic artery Cribriform plate Optic canal

Middle Cranial Fossa Fossa is formed by the: Greater wing of the sphenoid Squamous part of the temporal bone Petrous part of the temporal bone Greater wing of sphenoid Squamous portion temporal bone Petrous portion temporal bone

Middle Cranial Fossa Sella turcica- the saddle-like bony formation located on the superior aspect of the body of the sphenoid Sella turcica is surrounded by anterior & posterior clinoid processes Sella turcica Anterior and Posterior clinoids

Middle Cranial Fossa Sella turcica is composed of three parts: Hypophyseal fossa Tuberculum sellae Dorsum sellae Sella turcica is composed of three parts: Hypophyseal fossa (pituitary fossa) Tuberculum sellae (saddle horn) Dorsum Sellae (back of the saddle) Sella turcica- essentially houses and guards the pituitary gland

Middle Cranial Fossa Middle cranial fossa presents five important foramina: Superior orbital fissure for passage of CN’s III, IV, V1 & VI & ophthalmic veins Foramen rotundum which transmits the maxillary nerve (V2) Foramen ovale- which transmits the mandibular nerve (V3) Superior orbital fissure Foramen rotundum Foramen ovale

Middle Cranial Fossa Foramen spinosum which transmits the middle meningeal artery Foramen lacerum- nothing is transmitted vertically thru this foramen although the internal carotid artery and some nerves pass across the foramen horizontally Grooves for the greater & lesser petrosal nerves are located along the anterior slope of the petrous portion of the temporal bone Foramen spinosum Petrosal grooves Foramen lacerum

Middle Cranial Fossa Petrous portion of the temporal bone houses the middle and inner ear cavities Arcuate eminence- marks the roof of the anterior semicircular canal of the inner ear cavity Trigeminal impression is located just anteromedial the arcuate eminence Trigeminal impression Arcuate eminence

Posterior Cranial Fossa The largest & deepest of the three fossae Formed mainly by the occipital bone and the petrous & mastoid part of the temporal bone Occipital bone Temporal bone Petrous portion

Posterior Cranial Fossa Clivus marks the anterior portion of the occipital bone Foramen magnum- large foramen that marks the transition from the medulla to the spinal cord Posterior to the foramen magnum is the internal occipital crest and internal occipital protuberance clivus Occipital crest Internal occipital protuberance

Posterior Cranial Fossa Sulcus for transverse and S-shaped sigmoid sinuses (both dural venous sinuses) Jugular foramen 1-Internal jugular Vein 2-Inferior petrosal sinus 3-Glossopharyngeal (CN IX) 4-Vagus (CN X) 5-Accessory (CN XI) Jugular foramen Groove for the Sigmoid sinus Transverse Sinus groove

Posterior Cranial Fossa Internal acoustic meatus is located just anterosuperior to the jugular foramen Internal acoustic meatus transmits the facial nerve (CN VII) and vestibulochochlear nerve (CN VIII) along with the labyrinthine artery Hypoglossal canal for the hypoglossal nerve (CN XII) lies superior to the margin of the foramen magnum Internal acoustic meatus Hypoglossal canal

Cribrifrom plate-CN I Optic Canal CN II Superior Orbital Fissure CN III, IV, V1 & VI Hypoglossal Canal CN XII Jugular Foramen- CN IX, X and XI Internal Acoustic Meatus- CN VII & VIII Foramen Rotundum- CN V2 Foramen Ovale-CN V3

Mandible

Mandible = فک پایینی

Mandible = فک پایینی

Mandible = فک پایینی

Mandible Condylar Process Mandibular foramen Coronoid process Infant Coronoid process Mylohyoid line Lingula Ramus Alveolar Part (crest) Mental foramen Body 4/26/2017

Mandible Mandibular notch Condylar process Ramus Body Mental spines Bone loss due to tooth loss 4/26/2017

Hyoid لامی =

Hyoid Bone