Page 334 - Atlas of Histology with Functional Correlations

SECTION 1 Central Nervous System: Brain

and Spinal Cord

INTRODUCTION

The mammalian nervous system is the most complex system in the body. It is
divided into two major parts: the central nervous system (CNS) consists of the
brain and spinal cord that are surrounded and protected by the cranium and

vertebral bones, respectively, and the peripheral nervous system (PNS) located
outside of the CNS and consists of cranial, spinal, and peripheral nerves that
conduct information to (afferent or sensory) and from (efferent or motor) the
CNS.

PROTECTIVE LAYERS OF THE

CENTRAL NERVOUS SYSTEM

Nervous tissue is very delicate. Bones, connective tissue layers, and a watery
cerebrospinal fluid (CSF) surround and protect the brain and the spinal cord.

Deep to the cranial bones in the skull and the vertebral foramen are the
meninges, a connective tissue that consists of three distinct layers: the dura
mater, arachnoid mater, and pia mater (Fig. 9.1).

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