2Skull Defenition:it is the skeleton of the head * The skull is composed of several separate bones united at immobile joints called sutures (line of fusion) note??* Mandible is united to skull by mobile T.M.JParts of the skull:The skull is divided into 2 parts1- cranium OR skull cap2- Facial skeleton.
31- The cranium(skull cap): * The upper& post. Part which encloses the brain.It consists of the following bones: Frontal,parietal(2),occipital,temporal(2),sphenoidðmoid.2- Facial bones:* it’s the ant. Part of skull which includes:A- upper fixed part.B- lower movable part(mandible)* It consists of the following bones:Zygoamtic bone,maxillae,nasal,lacrimal,vomer,palatine,inf. Conchae,mandibleTotal : 22 bones
71- from sup. Aspect(or norma verticalis) For convinous of the description,the skull is described from various aspect:1- from sup. Aspect(or norma verticalis)2- from ant. Aspect(or norma frontalis)3- from lat. Aspect(or norma lateralis)4- from post. Aspect(or norma occipitalis)5- from inf. Aspect(or norma basalis)
81- from sup. Aspect(or norma verticalis) Now we are going to describe sup. Aspectof skull or norma verticalis:This superior aspect shows :1- frontal bone- anteriorly2- occipital bone-posteriorlyparietal bone- inbetween(on the side)
132- Ant. Aspect of skull (norma frontalis) The ant. Aspect shows:- forehead- orbital cavityNasal cavity seperated by nasal septumUpper & lower jaw
14Anatomical features: A- Forehead superciliary arches which are more prominent in male than female.nasofrontal suturenasionglabellaNote: in some cases the 2 halves of frontal bone persist in adult and called metapoic suture.
16B- Orbital cavityit’s pyramidal in shape having abase open into face & apex which it opens into cranial cavity.The base of orbit have 4 margins1- sup.2- inf.3-medial4- lateral
17sup. Orbital foramen which transmit supraorbital nerves&vesseles. the supratrochlear notch which transmit supraorbital nerves&vesseles.The inf. Orbital margin , it’s formed by maxilla medially& zygomatic bone laterallyinfraorbital foramen which transmit infraorbital N.&V.lacrimal fossaNote: the cavity of orbit has a roof , floor ,medial wall & lateral wall.Optic canal
18Inf. Orbital fissure communicate orbit with both infratemporal fossa & pterygopalatine fossa , it transmits continuation max. N. which is called infratemporal N. & branch of maxillary A. which is called infratemporal A.
23D- Maxilla*It’s enclose with maxillary air sinus to form upper jaw*The process with carry teeth it called alv. Process*The process which formed part of hard palate is called palatine process.Zygoamtic bone:It’s articulate with zygomatic process of temporal bone to form zygomatic arch which lies in lateral aspect of skull.