6 Neuroanatomy: Draw It to Know It
Overview of Neuroanatomy
To begin, we will draw an overview of the anatomy of
the nervous system. First, we will address the brain,
brainstem, and cerebellum. Begin with a coronal section
through the brain. From outside to inside, label the
meninges, which protect and nourish the nervous
system; the cortex, which constitutes the outer, cellular
gray matter portion of the brain; the subcortical white
matter, which constitutes the underlying nerve axons;
the basal ganglia, which are most notably involved in
motor function but are also important for behavioral
and cognitive functions; the thalamus, which in combi-
nation with the metathalamus relays most of the aff erent
information that enters the nervous system to various
regions throughout the cerebral cortex; the hypothala-
mus, which lies along the third ventricle and is the center
for autonomic nervous system function; and the cere-
brospinal fl uid system, which assists the meninges in
supporting and nourishing the nervous system.
Below the brain, draw the brainstem. From superior
to inferior, show the midbrain, identifi ed by its crus cere-
bri, then the pons, identifi ed by its bulbous basal out-
pouching, and fi nally the medulla. Th e brainstem
contains cranial nerve nuclei, which command oculob-
ulbar motility, facial sensation, and many craniofacial
and thoracoabdominal autonomic functions. And the
brainstem also contains many additional neuronal pools
essential for survival as well as the fi ber tracts that pass
between the brain and spinal cord. On the posterior
aspect of the brainstem, draw the leafy hemispheres of
the cerebellum; the cerebellum is important for balance
and orientation, postural stability, and coordination.
Next, we will address the spinal cord and peripheral
nervous system. Draw the long, thin spinal cord with
its cervical and lumbosacral enlargements. Label the
segments of the spinal cord from top to bottom as fol-
lows: cervical, thoracic, lumbosacral, and coccygeal. Th e
cervical segment mostly communicates with the upper
extremities, upper trunk, head, and neck; the thoracic
segment mostly communicates with the trunk and abdo-
men; and the lumbosacral segment communicates with
the abdominal-pelvic region and the lower extremities.
Draw a dorsal nerve root off of the posterior spinal
cord; identify it with its dorsal root ganglion, which
houses the sensory cell bodies. Th en, draw the ventral
root from the anterior surface of the spinal cord; it con-
tains the motor fi bers that exit from the gray matter of
the spinal cord. Next, show that the motor and sensory
roots meet to form a mixed spinal nerve within a neural
foramen. Th en, show that the cervical nerves interweave
to form the cervical and brachial plexuses. Now, indicate
that the lower lumbosacral nerve roots descend through
the lumbar cistern and exit the spinal canal to form the
lumbosacral plexus. Next, indicate that the majority of
the thoracic nerves remain unmixed. Th en, show that
aft er the nerves exit their plexuses, they continue as
peripheral nerve fi bers. Now, draw a representative neu-
romuscular junction and a sensory cell receptor and
attach muscle fi bers to them. Neurotransmissions pass
across the neuromuscular junctions to stimulate muscle
fi bers, and peripheral nerve receptors detect sensory
impulses from the musculoskeletal system and skin.
Lastly, to represent the divisions of the autonomic
nervous system, draw a parasympathetic ganglion and a
sympathetic paravertebral chain segment; the parasym-
pathetic nervous system is active in states of rest whereas
the sympathetic nervous system is active in states of
heightened awareness — it produces the “fi ght-or-fl ight”
response.