Surrounding the brain is a region of the skull known as the cranium. In this region we have eight cranial bones:

• Frontal bone:The frontal bone is made up of three parts. These are the squamous part, the orbital part and the nasal part. The squamous part marks the flat and also the biggest part, and the main region of the forehead. The orbital part is the horizontal and second biggest region of the frontal bone. It enters into the formation of the roofs of the orbital and nasal cavities. The nasal, the smallest, part articulates with the nasal bone and the frontal process of the maxilla to form the root of the nose.

• Two parietal bones: The parietal bones are two bones in the human skull which, when joined together at a fibrous joint, form the sides and roof of the cranium. Each bone is roughly quadrilateral in form, and has two surfaces, four borders, and four angles.

• Two temporal bones: The temporal bones are situated at the sides and base of the skull, and lateral to the temporal lobes of the cerebral cortex. The temporal bones are overlaid by the sides of the head known as the temples and house the structures of the ears. The lower seven cranial nerves and the major vessels to and from the brain traverse the temporal bone.

• Occipital bone: The occipital bone is a cranial dermal bone, and is the main bone of the occiput (back and lower part of the skull). It is trapezoidal in shape and curved on itself like a shallow dish. The occipital bone overlies the occipital lobes of the cerebrum. At the base of the skull in the occipital bone there is a large oval opening called the foramen magnum, which allows the passage of the spinal cord.
  Like the other cranial bones it is classed as a flat bone. Due to its many attachments and features the occipital bone is described in terms of separate parts. From its front to the back is the basilar part, at the sides of the foramen magnum are the lateral parts, and the back is named as the squamous part.
  The basilar part is a thick, somewhat quadrilateral piece in front of the foramen magnum and directed towards the pharynx. This is also called the basioccipital.
  The lateral parts of the occipital bone are on either side of the foramen magnum and these are also called the exoccipitals.
  The squamous part is the curved, expanded plate behind the foramen magnum and is the largest part of the occipital bone.

• Ethmoid bone: The ethmoid bone is an unpaired bone in the skull that separates the nasal cavity from the brain. It is located at the roof of the nose, between the two orbits. The cubical bone is lightweight due to a spongy construction. The ethmoid bone is one of the bones that make up the orbit of the eye.
  The ethmoid bone is an anterior cranial bone located between the eyes.It contributes to the medial wall of the orbit, the nasal cavity, and the nasal septum.The ethmoid has three parts: cribriform plate, ethmoidal labyrinth, and perpendicular plate. The cribriform plate forms the roof of the nasal cavity,the ethmoidal labyrinth consists of a large mass on either side of the perpendicular plate, and the perpendicular plate forms the superior two-thirds of the nasal septum.Between the orbital plate and the nasal conchae are the ethmoidal sinuses or ethmoidal air cells, which are a variable number of small cavities in the lateral mass of the ethmoid.
• Sphenoid bone: The sphenoid bone is an unpaired bone of the neurocranium. It is situated in the middle of the skull towards the front, in front of the temporal bone and the basilar part of the occipital bone. The sphenoid bone is one of the seven bones that articulate to form the orbit. Its shape somewhat resembles that of a butterfly or bat with its wings extended.

Collectively, these bones provide a solid bony wall around the brain, with only a few openings for nerves and blood vessels. Our occipital bone contains the foramen magnum, the hole through which the spinal cord enters the skull to attach to the brain. The occipital bone also forms the atlanto-occipital joint with the atlas (the first cervical vertebra in our spine).

The frontal, ethmoid, and sphenoid bones contain small hollow spaces known as paranasal sinuses. The sinuses help to reduce the weight of these bones and increase the resonance of the voice during speech, singing, and humming.