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This is a simple diagram of the part of the human nervous system.
Brainstorm and
write down at least 3 ideas of how this complex system helps us in so many ways.
Then share your ideas with a partner.
1.
2.
3.
7.4 Reading #1:
The Nervous System
The variety of animals shown in Figure 145 serves as an illustration
of the diversity in
structure and complexity of nervous systems throughout the animal kingdom. Some organisms don't
actually have a nervous system, like sea sponges. Others, like jellyfish, lack a true brain and instead
have what is known as a "nerve net," which is a network of distinct but linked nerve cells (neurons).
Sea stars and other echinoderms have nerves, which are composed of bundles of nerve cells. Both a
central nervous system (CNS), which consists of a small "brain" and two nerve cords, and a peripheral
nervous system (PNS), which is made up of a network of nerves that extends throughout the body,
are present in flatworms of the phylum Platyhelminthes. Insect nervous systems vary in complexity
and degree of centralization.
It includes ganglia,
the ventral nerve cord, and the brain (clusters of
connected neurons). These ganglia are capable of controlling actions and behaviors independently of
the brain. Octopi may have the most complex nervous system of any invertebrate because of their
specialized lobe-organized neurons and structurally related eyes to vertebrate species.
