Page 240 - Ultimate Visual Dictionary (DK)

THE HUMAN BODY

Nervous CENTRAL AND PERIPHERAL
NERVOUS SYSTEMS
Cranial Cerebrum
nerves
system Cerebellum

Cervical
nerves
THE NERVOUS SYSTEM IS THE BODY’S internal, Brachial
electrochemical, communications network. plexus
Its main parts are the brain, spinal cord, and
nerves. The brain and spinal cord form the
central nervous system (CNS), the body’s
chief controlling and coordinating Spinal
centers. Billions of long neurons, cord
Thoracic
many grouped as nerves, make
nerves
up the peripheral nervous system, transmitting
nerve impulses between the CNS and other
Radial
regions of the body. Each neuron has three
nerve
parts: a cell body, branching dendrites that
Median
receive chemical signals from other neurons, nerve
and a tubelike axon that conveys these
Ulnar
signals as electrical impulses. Lumbar nerve
nerves
Sacral
nerves

Sacral
plexus
SECTION THROUGH SPINAL CORD
Femoral
nerve Pudendal
nerve
Gray matter Central
Spinal canal Posterior root Sciatic
ganglion of spinal nerve nerve
Spinal nerve Cutaneous
nerve
Common
peroneal
nerve

Posterior
tibial nerve
White matter
Superficial
Anterior median fissure Anterior root peroneal
of spinal nerve nerve

Deep
peroneal
nerve

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