1. Chapter 7: The Nervous System Introduction - Page 222

2. The nervous system Master controlling and communicating system of the body Every thought, action, and emotion reflects its activity Signaling device: –Electrical impulses (rapid, specific & cause immediate response)

3. Three overlapping functions 1. Sensory input –Millions of sensory receptors to monitor changes occurring inside & outside the body –Changes are called stimuli 2. Integration –Processing and interpretation of sensory input –Makes decisions about what should be done 3. Motor output –Effects a response –Activates muscles or glands (effectors)

4. How do these functions work together? You are driving and see a red light ahead. How do these three functions work together? –1.? Give me an example sensory input? –2.? Give me an example integration? –3.? Give me an example motor output?

5. Organization of the nervous system Very complex We can divide it in terms of structures and functions

6. Structural Classification The nervous system has two subdivisions: –Central nervous system (CNS) Brain and spinal cord Integrating and command centers of the nervous system Interpret incoming sensory information and issue instructions based on past experience and current conditions –Peripheral nervous system (PNS) Nerves that extend from the brain and spinal cord Spinal nerves – carry impulses to and from the spinal cord Cranial nerves – carry impulses to and from the brain Think of communication lines

7. Functional Classification Concerned only with the PNS Two subdivisions: –1. Sensory (afferent) division Nerve fibers that convey impulses to the CNS from sensory receptors Sensory fibers delivering impulses from the skin, skeletal muscles, and joints are called somatic fibers Sensory fibers … form visceral organs are called visceral sensory fibers

8. Functional Classification (cont.) The second subdivision: –2. Motor (efferent) division Carries impulses from the CNS to effector organs, muscles, and glands Activate muscles and glands (that is, they effect or bring about a motor response)

9. The motor division has two subdivisions 1. The somatic nervous system –Allows us to consciously, or voluntarily, control our skeletal muscles –Sometimes called the voluntary nervous system 2. The automatic nervous system –Regulates events that are automatic, or involuntary (cardiac and smooth muscles) –Sometimes called the involuntary nervous system –Two parts: sympathetic and parasympathetic We’ll talk about this later

10. Confused? Take a look at the graphic organizer on page 224 Copy this graphic organizer in your notes. Homework: read pages 222-228 AGAIN!!! Bring book this week Expect a quiz on pages 222-228 Friday