1. Functions of the cranial bones:
1. Protect the brain
2. Inner surfaces attach to meninges (membranes covering the brain) to stabilize the brain and attach to blood vessels and nerves

2. More functions of cranial bones
3. Outer surface for muscle attachment for movement of the head

3. Cranial bones and their parts:
Cranium – has 8 bones:
1. Frontal bone (1) – forms the forehead, eye sockets (orbits) and most of the anterior part of the cranial floor.
A. Function: protect the frontal lobe of the brain.

4. Frontal bone continued
B. Parts:
a. Frontal sinus – spaces within the frontal bone that give resonance to the voice
b. Coronal suture – runs side to side, connects the frontal bone to the parietal bones.

6. Cranial bones and their parts continued:
2. Parietal bones (2) – form the sides and roof of the cranial cavity
A. Function: Protect the parietal lobe of the brain

7. Parietal bones continued
B. Parts:
a. Coronal suture – connection to the frontal bone
b. Sagittal suture – runs front to back and connects the 2 parietal bones
c. Lambdoid suture – connects the parietal bones to the occipital bone
d. Squamous suture – connect the parietal bones to the temporal bone

9. 3. Occipital bone
Occipital bone (1) – forms the posterior part and most of the base of the cranium.
A. Function : protects the occipital lobe of the brain

10. B. Parts:
a. Occipital condyles – visible on the underside. Oval processes that connect to the first cervical vertebrae.
b. Foramen magnum – large opening on the underside that contains the medulla oblongata and connects to the spinal cord, spinal arteries and vertebral arteries
c. Lambdoid suture – connects the parietal bones to the occipital bone

12. A. Function: Protects the temporal lobe
4. Temporal bones (2) – form the inferior sides of the cranial cavity and part of the cranial floor.
A. Function: Protects the temporal lobe

13. Temporal bones
B. Parts:
a. External auditory meatus – canal to the middle ear
b. Styloid process – attachment site for ligaments and muscles of the tongue and neck

14. More temporal bone parts
c. Zygomatic arch – joins with zygomatic bones to form this
d. Mandibular fossa – dip where the lower jaw attaches to create the tempromandibular joint (TMJ)

16. TMJ
TMJ syndrome is pain around the ear, a popping sound or pain when opening or closing the mouth, headache, abnormal wear of the teeth due to improper alignment of the joint.

17. 5. Sphenoid bone (1)
- Lies at the base of the skull
A. Function: holds the other cranial bones together in the cranial floor.

18. a. Optic foramen – the optic nerve passes through this opening
Sphenoid bone
B. Parts:
a. Optic foramen – the optic nerve passes through this opening
b. Sphenoidal sinus – spaces that drain into the nasal cavity

20. 6. Ethmoid bone (1)
– Light, spongy bone in the anterior part of the cranial floor between the orbits.
A. Function: Forms part of the cranial floor, the orbits and superior part of the nasal septum (separates nasal cavity into right and left sides) and most of the walls of the nasal cavity.

21. Ethmoid bone
B. Parts:
a. Cribiform plate – roof of the nasal cavity,
b. olfactory foramina – fibers of the olfactory nerve (smell) pass through here