Brain is protected by cranial bones, cranial meninges, and CSF.
Brain stem consists of the medulla oblongata, pons, and midbrain. Lower end is a continuation of the spinal cord.
Diencephalon consists primarily of the thalamus and hypothalamus.
Cerebrum spreads over the diencephalon and occupies most of the cranium.
Inferior to the cerebrum and posterior to the brain stem is the cerebellum.
Cranial meninges surround the brain and are continuous with the spinal meninges.
Tough fibrous structure containing an inner (meningeal) layer and outer (periosteal) layer
Most of the dura’s venous sinuses lie between the dural layers
Dural layers are generally fused, except where they separate to provide space for the venous sinuses and where the inner layer forms septa between the brain portions
Outer layer firmly attached to inner surface of cranial bones; inner layer continuous with spinal dura
Delicate avascular membrane covers the subarachnoid space
Between the arachnoid and dura mater lies the subdural space
Arachnoid granulations project into the superior sagittal sinus
Subarachnoid space between the arachnoid and the pia is relatively narrow over the surface of the cerebral hemisphere and is much wider at areas at the base of the brain
Thin connective tissue membrane that covers the brain surface and extends into sulci and fissures and around blood vessels throughout the brain
Invaginations of the pia form choroid plexuses of the ventricles
Various types of lesions, malformations, or pathology may present in one or more intracranial compartments