COMPARATIVE COMPARATIVE ANATOMY:ANATOMY:ANIMAL BODY SYSTEMSANIMAL BODY SYSTEMSNERVOUS SYSTEMNERVOUS SYSTEM

AISD - 2009

Nervous SystemNervous System Function: Recognizes and

coordinates changes in internal and external environments.◦ Control center of the

body. Invertebrate Organs

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?

Think about this…

Nervous System: Nervous System: Response to the Response to the environmentenvironment• 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.

Section 29-2

GangliaGanglia

Brain

BrainNerve Cells

Arthropod

Mollusk

CnidarianFlatworm

Figure 29–12 Figure 29–12 Invertebrate Nervous SystemsInvertebrate Nervous Systems

Think about this…

What is “Ganglia” ? How does it differ from a brain?Hint: You will need to look this up

Which nervous system seems to be the simplest? Why?

Pons

Pituitary gland

Hypothalamus

Cerebrum

Medulla oblongata Spinal cord

Cerebellum

Pineal gland

Thalamus

Section 35-3

Figure 35-9 The Brain

Brain stem

The Human Brain:The Human Brain:Control center of the Nervous Control center of the Nervous SystemSystem

Human Nerve Cell: Human Nerve Cell: Messenger of the nervous Messenger of the nervous systemsystem

Think about this…

What role does the neuron (nerve cell) play in response to a stimulus?