ABSTRACT
THIS CHAPTER includes the brain, lying within the cranial cavity of the skull, and the spinal cord, which extends through the cervical and thoracic parts of the vertebral column to the level of L1 vertebra. (See p. 20 for external features of the skull.)
Cranial cavity In life the cranial cavity is lined by the dura mater (3.1), the outermost and toughest of the three membranes or meninges that cover the brain (p. 49). In places the dura forms partitions that help to keep the brain in place: the falx cerebri, between the two cerebral hemispheres, and the tentorium cerebelli, forming a roof for the posterior cranial fossa, but with a large central gap for the brainstem to pass through. The dura also forms the venous sinuses of the skull (see below).
