General Anatomy Lecture 6 PDF

Academic year 2022-2023 ‫فرع جراحة الفم والوجه والفكين‬ ‫كلية طب االسنان‬ 1st year Human Anatomy Lecture 6...

Academic year 2022-2023 ‫فرع جراحة الفم والوجه والفكين‬ ‫كلية طب االسنان‬ 1st year Human Anatomy Lecture 6 Cranial Cavity By:Dr.Nada hashim AL JASSIM Snell R.S. Clinical Anatomy by regions, 9th Edition, Lippincott Williams & Wilkins,2012 For more detailed instructions, any question, cases need help please post to the telegram group of the session  The cranial cavity The cranial cavity, or intracranial space, is the space formed inside the skull. It is occupied by brain , its surrounding meninges , cerebrospinal fluid and vessels. Eight fused cranial bones together form the cranial cavity: the frontal, occipital, sphenoid and ethmoid bones, parietal and temporal bones. The cranial cavity Calvaria 3 4 2 5 7 1 6  Base of the skull Anterior cranial fossa The base of skull, also known as (the cranial floor). N It separates the brain Middle cranial fossa from other facial Structures N Divides into 3 fossae: *Anterior Posterior cranial fossa *Middle *Posterior Anterior cranial fossa What are the bones forming the anterior cranial fossa ? Orbital plates of cribriform 1 1 3 2 3 3 Borders are;: Anteriorly and laterally by the inner surface of the frontal bone. NPosteriorly (medially & laterally ) by the sphenoid bone  Floor is formed By Laterally by: orbital plates of the frontal bone (1) 5.  Centrally by the 4 cribriform plate of the ethmoid bone(2)  and Crestagalli (3). 3  Foramina cecum (4) : is 1 1 Small aperture between 2  the crista galli (3)  and the crest of the frontal bone (5). It transmits emissary veins from nose to superior sagittal sinus The floor contains tow foramen Middle cranial fossa  Bones forming middle cranial fossa : 1.Body and greater wing 1 of sphenoid 1 bone. 2.parts of 3 temporal 2 bone. 3.parts of parietal bone Boundaries  Floor (Central part) : It is formed by the body of the sphenoid bone which contains: *Chiasmatic groove (Sulcus) *Sella turcica that holds the pituitary gland and is surrounded by the anterior And posterior clinoid processes. They serve as attachment points for the tentorium cerebelli Sella turcica consists of three parts : 1.The tuberculum sellae : 2. The hypophysial fossa or pituitary fossa. 3. The dorsum sellae  Floor (Lateral part) The depressed lateral parts of the floor of middle cranial fossa are formed by N1.Greater wings of sphenoid N2. Squamous and petrous parts 1 of the temporal bones It is the site of many foramina – small holes by which vessels and 2 nerves enter and leave the cranial cavity. Foramina of middle cranial fossa ❖ Often some rays offer some heat ❖ Only some rabbits obey senior hares Foramina of middle cranial fossa ❖ Often some rays can offer sun light ❖ Only some readers can obey senior  Foramina of middle cranial fossa 7-Carotid canal: The internal carotid artery enters the foramen lacerum through this canal. **Trigeminal impression For trigeminal ganglion lies Lateral to the foramen lacerum, on the apex of the petrous part of the temporal bone Posterior cranial fossa  Foramina of posterior cranial fossa Foramen magnum: transmits Medulla oblongata and its surrounding meninges, spinal parts of the accessory nerves and two vertebral arteries also pass through it. Hypoglossal canal: transmits the hypoglossal nerve. Internal acoustic meatus Jugular foramen: Transmits the Glossopharyngeal (IX), Vagus (X) Accessory (XI) cranial nerves , Inferior petrosal sinus and Sigmoid sinus that becomes the internal jugular vein below the foramen). Internal acoustic meatus: transmits (facial (VII) vestibulocochlear(VIII)) I Just Had Macaroni  Posterior cranial fossa contains 1-Internal occipital crest for attachment of small falx cerebelli 2-Groove for superior sagittal sinus 3-Sulcus for transverse sinus 4-Cerebellar fossa THANK YOU