ANATOMICAL DETAILS OF CRANIAL BONES WITH VARIATIONS.ppt

ANATOMY OF CRANILA BONES

1. Human Skull

2. Human Skull – 22 bones
2 parts:
1.Cranium (8 bones fused at sutures) –
protects brain, provides muscle
attachment, sinuses reduce weight of skull
2.Facial (14 bones) – gives shape to face,
provides muscle attachment

3. Cranial Bones (8)
•Frontal (1) – forehead & upper eye orbits
•Parietal (2) – sides & roof of cranium
•Temporal (2) – sides & floor of cranium

4. Cranial Bones
Sphenoid (1) base & sides of cranium, parts of orbits
•Ethmoid (1) – walls of nasal cavities,
floor of cranium, orbits
•Occipital (1) – back & base of cranium

7. The Ethmoid Bone

8. Floor of Cranium

9. The Sphenoid Bone

11. Special Features of Temporal Bone –
1. zygomatic process – artic. w/zygomatic
bone
2. styloid process – anchors tongue &
pharynx muscles
3.mastoid process – attachment of neck
muscles
4.ext. auditory meatus – tube to middle ear

12. Special Features of Occipital Bone
1.Foramen magnum –
large opening for
brainstem to pass
through
2.Occipital condyles –
rounded projections
for articulation w/1
st

vertebrae

13. Facial Bones – 14 bones
Maxilla (2) – upper jaw,
roof of mouth;
(“keystone”)
Nasal (2) – bridge of
nose
Zygomatic (2) – cheek
bones, walls of orbits
Lacrimal (2) – medial
walls of orbits

14. Facial Bones - continued
•Inferior nasal
conchae (2) –
walls of nasal
cavities
•Mandible (1) –
lower jaw (only
movable bone in
skull)
•Vomer (1) –
nasal
septum

15. Facial Bones
Palantine (2) – roof of
mouth (hard palate)
(“cleft palate” –
incomplete fusion of
maxillae & palantine
bones)

16. Special Features of Facial Bones
Mandible - mandibular condyle –articulation
point w/temporal bone
coranoid process – provides
attachment for
chewing muscles

17. Special Features – Facial Bones
Zygomatic – has the temporal process; articulation point
w/temporal bone