ANATOMY OF HUMAN SKULL

SUBMITTED BY:VANDANA RANA

APGDCR ICRI, DEHRADUN

INTRODUCTION

SKULL:- skeleton of the head Also k/a CRANIUM Two parts:-

1.Calvaria 2.Facial Skeleton

Cont….

CALVARIA:- also k/a brain box

FACIAL SKELETON:- rest of the skull and mandible.

BONES OF THE SKULL

Calvaria – has 8 bones Two are paired and four are unpaired Paired bones are - 1.Parietal

2.Temporal Unpaired bones are- 1.Frontal

2.Occipital 3.Sphenoid

4.Ethmoid

Cont… Facial Skeleton bones:-there are 14 bones Two are unpaired and six are paired Paired:-1.Maxilla

2.Zygomatic3.Nasal4.Lacrimal

5.Palatine6.Inferior nasal concha

Unpaired:-1.Mandible 2.Vomer

SKULL JOINTS Immovable Exception is TMJ Fibrous k/a SUTURES

DIFFERENT VIEWS OF SKULL Exterior view:-these are as follows-

1.Superior or Norma Verticalis2.Posterior or Norma Occipitalis3.Anterior or Norma Frontalis4.Lateral or Norma Lateralis5.Inferior or Norma Basalis

Interior view:-after removing skull cap or calvaria1.Internal surface of the cranial vault.2.Internal surface of cranial base

Cont… Internal surface of cranial base can

further subdivided into:-1.Anterior cranial fossae2.Middle cranial fossae3.Posterior cranial fossae

NORMA VERTICALIS

Shape:-oval Bones:

1.upper part of frontal bone anteriorly2.uppermost part of occipital post

3.a parietal bone on each side Sutures:-

1.Coronal suture 2.Saggital suture 3.Lambdoid 4.Metopic suture

THANKS

Cont… Some other features are:-

1.Vertex2.Vault3.Bregma

5.Lambda6.Parietal Eminence7.Parietal Foramen8.Obelion9.Temporal Lines

NORMA OCCIPITALIS Bones are:- 1.posterior part of parietal

bones above 2.Squamous part of occipital bone below

3.mastoid part of temporal bone on each side

Sutures:- 1.Lambdoid suture2.Occipitomastoid suture3.Parietomastoid suture4.Posterior most part of

saggital suture also seen.

Cont… Other features:-

1.Lambda2.Parietal Foramina3.Obelion

4.External Occipital Protuberance5.Superior Nuchal Lines6.Highest Nuchal Lines7.Occipital point8.Mastoid Foramen9.Interparietal Bone

NORMA FRONTALIS Shape:-oval Bones:-

1.Frontal bone2.Maxilla-right and left

3.Nasal bone-right and left 4.Zygomatic bone 5.Mandible

Norma Frontalis is studied under following headlines:-

1.Frontal region2.Orbital opening3.Ant.bony(piriform) aperture of nose4.Lower part of face

Cont… Frontal region:-

1.Supercilliary arch2.Glabella3.Nasion4.Frontal eminence

Orbital opening:-bounded by1.Supra orbital margin

2.Infra orbital margin 3.Lateral orbital margin

Piriform aperture of nose:- pear shaped.bounded 1.above by lower boarder of nasal bone.2.below by body of maxilla on each side.

Various sutures are:-1.Internasal suture2.Frontonasal suture

Lower part of face:-1.Maxilla

2.Zygomatic bone3.Mandible

Cont… Sutures of Norma Frontalis:-

1.Internasal2.Frontonasal3.Nasomaxillary4.Lacrimomaxillary5.Frontomaxillary 6.Zygomaticomaxillary7.Zygomaticofrontal

NORMA LATERALIS Bones:-

1.Frontal2.Occipital3.Temporal4.Parietal5.Sphenoidal6.Zygomatic7.Mandible

8.Maxilla9.Nasal

Cont… Others features:-

1.Temporal lines2.Zygomatic arch3.External Acoustic Meatus4.Mastoid part of Temporal bone5.Styloid process6.Temporal fossa7.Pterion8.Infratemporal fossa9.Pterygopalatine fossa

NORMA BASALIS Norma Basalis is divided into three parts

as follows:-1.Anterior-subdivided into

*Hard Palate

*Alveolar Arch

2.Middle part3.Posterior part

Middle and posterior parts are seperated by imaginary lines passing through the anterior margin of foramen magnum.

ANTERIOR PART Alveolar arch bears sockets for the roots

of upper teeth. Hard palate:-sutures are as

1.Intermaxillary2.Interpalatine3.Palatomaxillary

Other features:-1.Incisive fossa

2.Greater Palatine Foramen3.Lesser Palatine Foramen4.Palatine Crest

MIDDLE PART Median area shows:-

1.Posterior boarder of vomer2.Broad bar of bone formed by fusion of posterior part of body of sphenoid and basilar part of occipital bone.

3.Pharyngeal Tubercle

Lateral area shows:-1.Two parts of sphenoid bone

*Pterygoid process(median and lateral) *Greater wing of sphenoid2.Three parts of temporal bone*Petrous

*Squamous *Tympanic plate

Cont… Infratemporal surface of greater wing of

sphenoid is pierced by1.Foramen Ovale2.Foramen Spinosum

3.Emissary sphenoidal foramen Inferior surface of pterion is pierced by

1.Carotid Canal2.Foramen Lacerum

Tympanic part of temporal bone has1.anterior surface which forms posterior wall of mandibular fossa.2.posterior part forms part of EAM

POSTERIOR PART Median area has

1.Foramen Magnum2.Externa Occipital Crest3.External Occipital Protrubrance

Lateral area has1.Condylar part of occipital bone2.Squamous part of occipital bone3.Juglar Foramen4.Styloid process5.Mastoid part of temporal bone

INTERIOR VIEW OF SKULL

Internal surface of cranial vault Internal surface of base of the skull

INTERNAL SURFACE OF CRANIAL VAULT

Most of the features have been explained with Norma Verticalis.

Few more are:-*inner table is thin and brittle. *it presents markings produced by meningeal vessels,venous sinuses. *frontal crest

*sagittal sulcus*granular foveolae

*cerebral gyri impressions

INTERNAL SURFACE OF BASE OF SKULL

Subdivisions are:-1.Anterior Cranial Fossa

2.Middle Cranial Fossa3.Posterior Cranial Fossa

ANTERIOR CRANIAL FOSSA Boundaries:-

1.Anteriorly and on sides by Frontal bone.2.Posteriorly separated from the

middle cranial fossa by the free posterior boarder of lesser wing of sphenoid,anterior margin of sulcus chiasmatics.

Floor:-1.In median plane formed anteriorly by

cribriform plate and posteriorly by anterior part of body of sphenoid.

2.On each side floor formed by orbital plate of frontal bone and lesser wing.

Cont…

Other features are:-1.Cribriform Plate of ethmoid

bone. 2.Juglar Sphenoidale3.Orbital plate of frontal

bone 4.Lesser wing of sphenoid

MIDDLE CRANIAL FOSSA

Boundaries :- Anterior by:-

1.Posterior boarder of lesser wing2.Anterior Clinoid Process

3.Anterior margin of sulcus chiasmatis Posterior by:-

1.Superior boarder of petrous temporal bone

2.Dorsum sellae of sphenoid Lateral by:-

1.Greater wing2.Anteroinferior angle of parietal3.Squamous temporal

Cont… Floor :-

1.median area by body of sphenod.2.lateral area by *cerebral surface of greater wing*anterior surface of petrous temporal.*cerebral surface of squamous temporal

Cont… Other features :- Median area has

1.Sulcus Chiasmatis(optic groove)2.Optic Canal3.Sella turcica

Lateral area is deep and lodges the temporal lobe of brain.It is related to orbit anteriorly,temporal fossa laterally,infratemporal fossa inferiorly.

Cont… Superior orbital fissure opens anteriorly into

orbit. The greater wing of sphenoid has following

features:- 1.Foramen Rotundum 2.Foramen Ovale 3.Foramen Spinosum 4.Emissary Sphenoidal Foramen 5.Foramen Lacerum

POSTERIOR CRANIAL FOSSA Boundaries are Anterior :-

1.Superior boarder of petrous temporal bone.

2.Dorsum sellae of sphenoid Posterior:- squamous part of occipital bone. On each sides by:-

1.Mastoid part of temporal2.Mastoid angle of parietal

Cont… Floor divided into two areas. Median area:-

1.Dorsum area in front2.Foramen magnum in middle3.Squamous occipit behind

Lateral area:-1`.Condylar part of occipital bone `2.post surface of petrous temporal3.Mastoid temporal4.Mastoid angle of parietal

THANK YOU