1.43. Peripheral Nervous System http://www.ck12.org
of the brain receives and interprets information from each sense organ. For example, information from the nose is
received and interpreted by the temporal lobe of the cerebrum.
FIGURE 1.79
Which senses would be stimulated by these raspberries?The Motor Division
Themotor divisionof the peripheral system carries messages from the central nervous system to internal organs
and muscles. The motor division is also divided into two parts (Figure1.78), the somatic nervous system and the
autonomic nervous system.
Thesomatic nervous systemcarries messages that control body movements. It is responsible for activities that are
under your control, such as waving your hand or kicking a ball. The girl pictured below (Figure1.80) is using her
somatic nervous system to control the muscles needed to play the violin. Her brain sends messages to motor neurons
that move her hands so she can play. Without the messages from her brain, she would not be able to move her hands
and play the violin.
FIGURE 1.80
This girl’s central nervous system is con-
trolling the movements of her hands and
arms as she plays the violin. Her brain
is sending commands to her somatic ner-
vous system, which controls the muscles
of her hands and arms.Theautonomic nervous systemcarries nerve impulses to internal organs. It controls activities that are not under
your control, such as sweating and digesting food. The autonomic nervous system has two parts:
- Thesympathetic divisioncontrols internal organs and glands during emergencies. It prepares the body for
fight or flight (Figure1.81). For example, it increases the heart rate and the flow of blood to the legs, so you
can run away from danger.