1. SHANDONG UNIVERSITY Liu Zhiyu
Skull
SHANDONG UNIVERSITY
Liu Zhiyu

2. Skull
The skull is composed of 23 bones, which may be divided into the cerebral craniumand facial cranium

3. Skull
Cerebral cranium (8) ―larger, upper and posterior part, contains and protects the brain
Single bones: include
frontal bone
ethmoid bone
sphenoid bone
occipital bone
Paired bones: include
temporal bone
parietal bone

4. Skull
Bones of facial cranium (15) ―smaller, lower, and anterior part, contains bones that surrounded the eye, nose and mouth
Single bones: include
mandible
vomer
hyoid bone
Paired bones: include
maxilla
nasal bone
lacrimal bone
palatine bone
zygomatic bone
inferior nasal concha

5. Bones of facial cranium

6. parietal bone
Frontal bone
Sphenoid bone
Temporal bone
Zygomatic bone
Occipital bone
Nasal bone
Maxilla
Mandible

7. Mandible Body of mandible Superior border: alveolar arch
Inferior border: base of mandible
Outer surface: mental protuberance
Mental foramen
Inner surface: mental spine
Digastric fossa

8. Mandible Ramus Mandibular notch Coronoid process Condylar process
head of mandible
neck of mandible
Mandibular foramen
Mandibular lingula
Angle of mandible
Masseteric tuberocity

9. The skull as a whole

10. Skull viewed from above (superior view)
Bones:
frontal bone
paired parietal bone
occipital bone
Sutures:
Coronal suture
Sagittal suture
Lambdoid suture
parietal tuber
parietal foramen

11. Skull viewed from above (superior view)
Internal surface of the calvaria
sulcus for superior sagittal sinus
granular foveola
arterial grooves

12. Skull viewed from behind
External occipital protuberance
Superior nuchal line
Inferior nuchal line

13. Internal view of base of skull
Base of skull forms three fossae
Anterior cranial fossa
Middle cranial fossa
Posterior cranial fossa

14. Internal view of base of skull

15. Anterior cranial fossa
Formed by orbital part of frontal bone, cribriform plate of ethmoid, and lesser wings of sphenoid
Structures:
frontal crest
foramen cecum
crista galli
cribriform plate
cribriform foramina

16. Meddle cranial fossa Structures:
Formed by the body and greater wings of sphenoid, petrous part of temporal
Structures:
Body of sphenoid bone
Hypophysial fossa
Optic canal
Anterior clinoid process
Tuberculum sellae
Dorsum sellae
Posterior clinoid process
Sella turcica

17. Meddle cranial fossa Carotid sulcus Superior orbital fissure
Foramen rotundum
Foramen ovale
Foramen spinosum
Sulcus for middle meningeal artery
Foramen lacerum
Internal opening of carotid canal
Trigeminal impression
Arcuate eminence
Tegmen tympani

18. Posterior cranial fossa
Formed by occipital and the petrous part of temporal
Structures:
foramen magnum
clivus
internal opening of hypoglossal canal
internal occipital protuberance
internal occipital crest
sulcus for transverse sinus
sulcus for sigmoid sinus
jugular foramen
internal acoustic pore
internal acoustic meatus

19. Skull viewed from below (inferior view)
alveolar arch
bony palate
median palatine suture
incisive foramina
incisive canal
greater palatine foramen
posterior nasal apertures
pterygoid process
occipital condyle
external opening of hypoglossal canal
external opening of carotid canal
styloid process
stylomastoid foramen
mandibular fossa
articular tubercle

20. Lateral view of the skull
External acoustic pore
Mastoid process
Zygomatic arch
Temporal fossa
Pterion
Superior temporal line

21. Lateral view of the skull
Infratemporal fossa
pterygomaxillary fissure
pterygopalatine fossa
sphenopalatine foramen

22. Skull viewed from the front (anterior view)
Frontal region:
frontal squama
frontal tuber
superciliary arch
glabella

23. Orbit Base: supraorbital notch infraorbital foramen Apex: optic canal
pyramid-shaped paired cavities
Base: supraorbital notch infraorbital foramen
Apex: optic canal
Walls
Superior:
fossa for lacrimal gland
Medial:
fossa for lacrimal sac
Inferior:
infraorbital fissure
infraorbital groove
infraorbital canal

24. Bony nasal cavity Roof: cribriform plate of ethmoid Floor: bony palate
Medial wall ― bony septum of nose
Lateral wall
Superior, middle and inferior nasal conchae
Superior, middle and inferior nasal meatus (underlying each concha)
Sphenoethmoidal recess
above superior nasal concha
Anterior ―piriform aperture
Posterior ―posterior nasal aperture
communicates with pharynx

25. Paranasal sinuses Frontal sinus
Lies in frontal bone, deep to superciliary arch
Drain to anterior part of middle meatus

26. Paranasal sinuses Maxillary sinus
Largest paired sinus, lie in the body of maxilla;
Opening into middle nasal meatus

27. Paranasal sinuses Ethmoidal cellules
Lie in ethmoidal bone, contains large number of air cells, divided into anterior, middle and posterior groups
Anterior and middle groups drain into middle nasal meatus, while posterior group drains into superior nasal meatus

28. Paranasal sinuses Sphenoidal sinus Lies in body of sphenoid bone
Drain into sphenoethmoidal recess

29. General characters of the skull at birth
The skull at birth is large in proportion to rest of the skeleton ―1/4 (adult 1/7)
The facial portion equals about one eight that of the cranium in size, whereas in adult it is one half (1/4)
Many bones consist of more than one piece

30. General characters of neonatal skull
Cranial frontanelles ―unossified membrane between the bones at the angles of parietal
Anterior frontanelle ―closes during middle of 2nd year
Posterior frontanelle ―closes by the end of 2nd month after birth
Mastoid fontanelle
Sphenoidal fontanelle

31. Anteroposterior radiograph of skull.

32. Lateral radiograph of skull.

33. Horizontal CT at level of upper part of ramus of mandible showing relationships of the pterygoid plates.