1. The Nervous System JORDIE SMELLS LIKE FEET IN THE SUMMER ON A HOT DAY BECAUSE HE LIKES TO EAT “HOTDOGS” ALL THE TIME.

2. Organization of the body  The levels of organizations in a multicellular organism goes as follows:  Cells, tissues, organs and organ systems.  There are 11 organ systems that help maintain homeostasis.

3. Homeostasis  It means to keep things in balance.  Homeostasis keeps internal conditions relatively constant despite change to external environments.

4. Feedback Inhibition  The process in which the stimulus produces a response that opposes the original stimulus.  Systems controlled by feedback inhibition are generally fully automated and very stable.  Ex: Like a thermostat.

5. The Actual Nervous System  The nervous system controls and coordinates function throughout the body and responds to internal and external stimuli.  The messages carried by the nervous system are electrical signals called impulses.  These cells are called neurons.  These cells are called neurons.

6. CONTINUED  The largest part of a typical neuron is the cell body, it contains the nucleus and much of the cytoplasm.  The dendrites which are attached to the cell body, carry impulses from the environment or other neurons to the cell body.  It is then carried away from the cell body through a long fiber called the AXON.  It is then carried away from the cell body through a long fiber called the AXON.

7. CONTINUED AGAIN  The axon is surrounded by the myelin sheath.  The myelin sheath basically increases the speed at which a impulse can travel.

8. The Synapse  The synapse is the location at which a neuron can transfer an impulse to another cell.  NEUROTRANSMITTERS are chemicals used by a neuron to transmit an impulse across a synapse to another cell.  NEUROTRANSMITTERS are chemicals used by a neuron to transmit an impulse across a synapse to another cell.

9. Central Nervous System  It relays messages, processes information & analyzes information.  It consists of the brain and spinal cord.  It consists of the brain and spinal cord.  Cerebrospinal fluid bathes the brain and spinal cord and acts as a shock absorber to protect the central nervous system!  It allows for exchange of nutrients and waste products between blood and nervous tissue.  It allows for exchange of nutrients and waste products between blood and nervous tissue.

10. The Brain  Pinky and the Brain are awesome.  Pinky and the Brain are awesome.  The cerebrum is the largest part of the brain, its responsible for intelligence, learning, and judgment.

11. Still part of the Brain  The cerebellum is the second largest part of the brain.  It coordinates and balances the actions of the muscles so the body can move efficiently.

12. More Brain Parts  The Brain Stem connects the brain and spinal cord.  It regulates the flow of information between the brain and the rest of your body.  Blood pressure, heart rate, breathing & swallowing are controlled by the BRAIN STEM!  Blood pressure, heart rate, breathing & swallowing are controlled by the BRAIN STEM!

13. The other part of the central nervous system  The spinal cord is the main communication link between the brain and the rest of the body.  A reflex is a quick automatic response to a stimulus such as SNEEZING and BLINKING.  A reflex is a quick automatic response to a stimulus such as SNEEZING and BLINKING.  I know you all blink.

14. The Peripheral Nervous System  It is divided up into the sensory division and motor division.  Sensory division takes care of the senses, such as smell, seeing, hearing, feeling and taste.  Motor division takes care of movements, such as thrusting and walking.

15. The Somatic and Autonomic System  The somatic system is anything you have conscious control over.  Such as, moving you finger around, and wiggling your tongue unbelievably fast.  The autonomic system is anything you DON’T have conscious control over.  Such as breathing heavily and blinking.

16. The Eye  It sees stuff.  Light enters the eye through the cornea, the cornea helps focus the light which then passes through the chamber filled with fluid called the aqueous humor.  At the back of this chamber is the iris, the color part of the eye with an opening called the pupil.

17. More Eye Stuff  There are two types of photo receptors.  Rods.  Cones.  Rods are extremely sensitive to light but they do not distinguish different colors.  Cones are less sensitive then rods but they do respond to light of different colors producing color vision.

18. Drugs  Stimulates increase heart rate, blood pressure, in addition stimulates increase the release of neurotransmitters at some synapse in the brain.  Depressants slow down heart rate, breathing rate, lower blood pressure, relax muscles and relieve tension.

19. More Drugs  COCAINE causes sudden release in the brain of neurotransmitters called dopamine.  Opiates mimic natural chemicals in the brain known as endorphins, which normally help to overcome sensations of pain.

20. THE END By: Sassie and Sierra and then Jordie.