1. Objectives 31.3 The Peripheral Nervous System
-Describe the functions of the sensory division of the peripheral nervous system.
-Describe the functions of the motor division of the peripheral nervous system.

2. The Peripheral Nervous System
The peripheral nervous system consists of all the nerves and associated cells that are NOT part of the brain or spinal cord.

3. The Sensory Division
The sensory division of the peripheral nervous system transmits impulses from sense organs to the CNS.

4. Sensory receptors are categorized by the type of stimuli to which they respond.

5. The Motor Division
The motor division of the peripheral nervous system transmits impulses from the central nervous system to muscles or glands.

6. Somatic Nervous System
The somatic nervous system regulates body activities that are under conscious control, such as the movement of skeletal muscles.

7. Reflex Arcs
The somatic nervous system also controls your reflex responses.
For example, if you accidentally step on a tack with your bare foot, your leg may recoil before you are even aware of the pain.
This rapid response (a reflex) is caused by impulses that travel a pathway known as a reflex arc.

8. Reflex Arcs

9. Autonomic Nervous System
The autonomic nervous system regulates activities that are involuntary, or not under conscious control.

10. Autonomic Nervous System
The autonomic nervous system consists of two parts, the sympathetic nervous system and the parasympathetic nervous system.
In general, the sympathetic and parasympathetic systems have opposite effects on each organ they influence. Heart rate is increased by the sympathetic nervous system but decreased by the parasympathetic nervous system.

11. True or False
Sensory receptors that alert your brain when it is cold outside are called thermoreceptors. _________________________ The muscles in your stomach responsible for churning and mixing food are controlled by the somatic nervous system. _________________________ During brain surgery, patients are sometimes kept awake. This is possible because the brain does not contain chemoreceptors. ______________________________

12. Answers
Sensory receptors that alert your brain when it is cold outside are called thermoreceptors.True The muscles in your stomach responsible for churning and mixing food are controlled by the somatic nervous system. False, autonomic During brain surgery, patients are sometimes kept awake. This is possible because the brain does not contain chemoreceptors. False, pain receptors