<p></p><p></p><h2><a>The Central Nervous System (CNS)</a></h2><p>The central nervous
system includes the brain (contained within the skull), which weighs 1.3–1.4 kg
in humans, and also the spinal cord, which extends into the vertebral canal.
The brain is grossly divided into the brainstem, cerebellum, and cerebrum. The
cerebrum is further divided into the basal ganglia, limbic system, and
neocortex.</p><img src="@@PLUGINFILE@@/CNS.jpg" alt="Central Nervous System" width="424" height="839" class="img-responsive atto_image_button_middle"><br><p><i>Figure 2a: The major components of the Central Nervous System</i></p><p></p><h2><a></a><a>Spinal cord</a></h2>

<p>The spinal
cord descends from the brainstem down through the shielded tunnel of the
vertebrae,&nbsp; and transmits information
from the body to the brain and from the brain to the body. Thus, the central
nervous system is composed of nerves the are rooted to both the surface of the
brain, as well as to the spinal cord. Most nerves are peripheral nerves, which
extend and branch toward the surface of the body.</p><p><img src="@@PLUGINFILE@@/Spinal%20Cord%20.jpg" alt="Spinal Cord anatomy" width="372" height="471" class="img-responsive atto_image_button_middle"><br></p><p><i>Figure 2b: Anatomy of the Spinal Cord</i></p><p><i><img src="@@PLUGINFILE@@/PNS.jpg" alt="Peripheral Nervous System" width="723" height="917" class="img-responsive atto_image_button_text-bottom"><br></i></p><i>&nbsp;Figure 2c: The Spinal Cord, Peripheral Nerves, and Sympathetic &amp; Parasympathetic Nervous System</i><p><span></span></p><h2><span>Maclean's Triune Brain Theory</span></h2><p><span></span></p><div>

<p>The brain grows, layer upon layer, like an onion. Brain cells generating grab onto a guide wire,
which is a glial
fiber, a glial highway, with the nucleus
in the back. No other kind&nbsp;<span>of cell has to do this. Neurons travel in waves,
which scientists call migration.
&nbsp;In terms of the distances relative to their size, they are making an odyssey, without &nbsp;mistakes telling
them where to go in the brain.</span></p><p><span>Here is a cool video made by the Pasterkamp lab, outlining the signaling events and molecular mechanisms involved in the formation of neuronal connections during development.</span></p><p><a href="https://youtu.be/ZWACm6BkDVo">&nbsp;</a></p><br></div><br><br>