2. Nervous System

3. Nervous system cells  Neurons

4. Glial cells OBJ 43

5. Types of neurons sensory neuron (from senses) interneuron (brain & spinal chord) motor neuron (to muscle or gland…effector cells)

6. Human brain 1 2 3 4 5 6 7 8

7. Divisions of the nervous system

8. Nervous System Pathway OBJ 40

9. How messages travel ABC DEF G B CD E Synapse

10. Synapse: synapse Junction between nerve cells  1st cell releases neurotransmitter to trigger next cell

11. What are some examples of neurotransmitters?  Acetylcholine  Epinephrine (adrenaline)  Dopamine  Serotonin  Endorphins OBJ 45

12. Simplest Nerve Circuit  Reflex arc, or automatic response  signal only goes to spinal cord  essential actions  don’t need to think or make decisions about  blinking  balance  pupil dilation  startle

13. Drugs & the Nervous system What happens when you interfere with neural communication?

14. Nicotine  acts as a stimulant  mimics acetylcholine  triggers the release of dopamine, making it addictive

15. Alcohol  Alcohol in drinks is actually ethyl alcohol  High concentrations can be toxic  Alcohol is a depressant  Excessive amounts of alcohol damages liver, digestive system, AND NEURONS

16. Alcohol and teens  Teens’ brains are specially geared for optimal learning  So, teens experience more severe damage to brain due to alcohol use (more blackouts, more brain damage…smaller brain)

17. Drug effects  What is going on when someone is addicted to drugs?  Opiate drugs (heroin, morphine) can mimic endorphins (a feel-good NT)  Body adjusts to higher amount of endorphin- like chemicals, and can’t do without it  Take more and more of the drug. Without it, feel pain, nausea, chills, fever, depression

18. Drug effects  Marijuana (THC) –  THC blocks the action of neurotransmitters in the brain affecting motor skills, memory, concentration  Long-term effects: loss of memory, inability to concentrate, lowered testosterone

19. Drug effects  Ecstasy (MDMA)  Causes rush of serotonin  Interferes with homeostasis (temp.)  Feel depressed until body makes enough of its own serotonin to feel ‘normal’ again  Destroys serotonin neurons axons and terminals  After exposure to MDMA for 4 days, it takes more than 7 years for your brain to recover.

20. Drug effects  Hallucinogens  LSD  PCP  Interfere with neurotransmitters in brain

21. Drug effects  Cocaine  Causes dopamine to be released  Not enough is left for normal function, so users become dependent on it Even 100 days after a cocaine addict has stopped using drugs, the decreased metabolism in the brain's frontal area remains visible. This region of the brain influences behavior such as regulating impulsive and repetitive behavior, planning and organizing activities, and critical thinking.