1. The Nervous System A Brief Overview!

2. What you will understand at the end of this lecture:  Functions of the nervous system  Divisions of the nervous system  Parts of the nervous system  Nerve cell (neuron) structure  How a message travels throughout your body  Functions of the nervous system  Divisions of the nervous system  Parts of the nervous system  Nerve cell (neuron) structure  How a message travels throughout your body

3.  Communication!  Receive info  Process info  Respond to info  Maintain homeostasis  Homeostasis: the process of maintaining the balance inside your body, regardless of your external environment (ex. Maintaining a normal temperature)  Communication!  Receive info  Process info  Respond to info  Maintain homeostasis  Homeostasis: the process of maintaining the balance inside your body, regardless of your external environment (ex. Maintaining a normal temperature) Nervous System Functions

4.  Thinking  Feeling  Moving  Tasting  Seeing  Hearing  Talking  Smelling  Touching  Thinking  Feeling  Moving  Tasting  Seeing  Hearing  Talking  Smelling  Touching

5. Function #1: Receiving Info  Nervous System receives info from INSIDE and OUTSIDE your body  Helps you be AWARE of your surroundings  Keeps internal body conditions in check (normal) ex. Blood sugar level, heart rate, temperature  Nervous System receives info from INSIDE and OUTSIDE your body  Helps you be AWARE of your surroundings  Keeps internal body conditions in check (normal) ex. Blood sugar level, heart rate, temperature

6. Function #2: Responding to Info  STIMULUS: signal that triggers nervous system to react  Ex. Mosquito buzzing, phone ringing, ball flying toward your face  NS responds to stimulus  RESPONSE: what your nervous system tells your body to do to react to the stimulus  Ex. You hit mosquito, you answer phone, you catch the ball  STIMULUS: signal that triggers nervous system to react  Ex. Mosquito buzzing, phone ringing, ball flying toward your face  NS responds to stimulus  RESPONSE: what your nervous system tells your body to do to react to the stimulus  Ex. You hit mosquito, you answer phone, you catch the ball

7. Divisions of the Nervous System  Central Nervous System  Peripheral Nervous System http://www.thepharmamarketing.com/imgposter/CH5183.jpg

8. Central Nervous System  Brain and spinal cord  Brain: controls body’s functions  Spinal cord: connects brain to nerves of peripheral nervous system to relay messages

9. Peripheral Nervous System  Somatic Nervous System  Controls VOLUTARY actions  Somatic Nervous System  Controls VOLUTARY actions  Autonomic Nervous system  Controls tasks you do not think about  Breathing, heart rate, body temp.  Divided into sympathetic and parasympathetic systems Divided into Somatic and Autonomic Nervous system

10. Peripheral Nervous System http://www.montana.edu/wwwai/imsd/rezmeth/anatomy.htm

11. Peripheral Nervous System Fight or flight Calm- ing Energy Conser- vation http://www.drstandley.com/images/nervous5.bmp

12. Nervous System Organization http://homepage.psy.utexas.edu/homepage/class/Psy301/Salinas/sec2/Brain/transparencies03.ht ml

13. Organization  Cells --> tissues --> organs --> organ systems  Nerve cell --> nerves --> brain --> central nervous system (brain and spinal cord)  Nerve - bundle of nerve cells held together by connective tissue  Cells --> tissues --> organs --> organ systems  Nerve cell --> nerves --> brain --> central nervous system (brain and spinal cord)  Nerve - bundle of nerve cells held together by connective tissue

14. Neuron Structure  Specifically designed to carry messages  Main parts: Dendrites, cell body, axon, axon tip  Specifically designed to carry messages  Main parts: Dendrites, cell body, axon, axon tip

15. Neuron Structure  Dendrites: receives incoming stimulus, sends message to cell body  Cell body: contains organelles, passes message to axon  Axon: carries message (impulse) awas from the cell body towards the next neuron’s dendrites  Axon tip: end of axon, message reaches here and jumps to next neuron’s dendrites  Dendrites: receives incoming stimulus, sends message to cell body  Cell body: contains organelles, passes message to axon  Axon: carries message (impulse) awas from the cell body towards the next neuron’s dendrites  Axon tip: end of axon, message reaches here and jumps to next neuron’s dendrites

16. Neuron to Neuron: Passing the message along http://www.ascd.org/ASCD/images/publications/books/sprenger1999_fig1.2.gif

17. Neuron to Neuron: Passing the message along http://psych.hanover.edu/krantz/neurotut.html

18. Neuron Types  Sensory neuron: senses stimulus, changes it into an impulse  Interneuron: passes impulse from neuron to neuron  Motor neuron: sends impulse to muscle or gland or part of body that needs to respond to stimulus  Sensory neuron: senses stimulus, changes it into an impulse  Interneuron: passes impulse from neuron to neuron  Motor neuron: sends impulse to muscle or gland or part of body that needs to respond to stimulus

20. Neurons (SEM picture)

21. Nerve Impulse (Message)  Travels from dendrites --> cell body --> axon --> axon tips --> jumps synapse (space between 2 neurons) --> dendrites --> cell body --> axon --> axon tips  Impulses can travel 120 m/s  Impulses travel across synapse either as an electrical signal or a chemical signal  Travels from dendrites --> cell body --> axon --> axon tips --> jumps synapse (space between 2 neurons) --> dendrites --> cell body --> axon --> axon tips  Impulses can travel 120 m/s  Impulses travel across synapse either as an electrical signal or a chemical signal