NSC 4366 Chapter Notes - Chapter 5: Cranial Cavity, Arachnoid Mater, Superior Orbital Fissure
Document Summary
The cns is supported and protected by bone and membranous coverings. Within the coverings, the brain and spinal cord is invested in three concentric membrane envelopes: dura mater outermost membrane, arachnoid mater middle layer, pia mater innermost layer. Brain lies on the floor of the cranial cavity, which, together with the bones of the cranial vault. Provides support and protection from physical injury. Cranial cavity consist of three fossae: each of these accommodates particular parts of the brain and possesses foramina. Pass the optic (ii) nerve and the ophthalmic artery: superior orbital fissure lies between the greater and lesser wings of the sphenoid bone. Posterior cranial fossa: formed by the occipital and petrous temporal bones. In the midline, it forms a steep, smooth slope (clivus) that is continuous with the body of the sphenoid bone, posterior to the hypophyseal fossa.
