AISD - 2009
COMPARATIVE ANATOMY:
ANIMAL BODY SYSTEMS
NERVOUS SYSTEM
Nervous System

Function: Recognizes and
coordinates changes in internal and
external environments.
◦ Control center of the body.

Invertebrate Organs


Think
about
this…
Nerve nets, ganglia, nerve rings
Vertebrate Organs
◦ Main organs



Brain
Spinal cord
Peripheral nerves
Describe internal and external conditions that an organism would
respond to?
Which organs allow you to respond?
How does the body perceive or “know” what is occurring?
Nervous System:
Response to the environment
All animals respond to their environment
through specialized cells called nerve cells
(neurons).
• In most animals nerve cells hook together to
form the nervous system.
• Nervous systems can range from fairly simple
to extremely complex.
• The arrangement of nerve cells from phylum to
phylum can be dramatically different.
•
Figure 29–12
Section 29-2
Invertebrate Nervous Systems
Arthropod
Brain
Ganglia
Ganglia
Brain
Nerve
Cells
Think
about
this…
Cnidarian
Flatworm
Which nervous system seems to be the simplest? Why?
Mollusk
What is “Ganglia” ? How does it differ from a brain?
Hint: You will need to look this up
Figure 35-9 The Brain
The Human
Brain:
Section 35-3
Control center of the Nervous System
Cerebrum
Thalamus
Pineal
gland
Hypothalamus
Cerebellum
Pituitary gland
Pons
Brain stem
Medulla oblongata
Spinal cord
Human Nerve Cell:
Messenger of the nervous system
Think
about
this…
What role does the neuron (nerve cell) play in response to a stimulus?