2. Addiction to psychoactive drugs is ______________________.

3. Your mood may be affected by your ___________________ level.

4. Narcotics block pain signals from reaching the _______________________.

5. The body produces ____________________ (a type of endorphine) to naturally combat pain.

6. Cocaine is a ____________________, not a narcotic.

7. Psychoactive drugs affect the nervous system and are _____________________.

8. ____________________ regulate the amount of neurotransmitters present in a synapse.

9. ____________________ use increases the number of opiate receptors in the spinal neurons.

10. ____________________ (such as LSD and mescaline) distort the way the brain reads sensory messages.

11. ____________________ has a wide range of effects, including those associated with alcohol and hallucinogens.

12. Cocaine blocks the reabsorption of the neurotransmitter, ____________________.  

13. Cigarettes contain ____________________ and tars.

14. Smoking enlarges the liver, which can lead to ____________________ (which can be fatal).

15. Alcohol changes the cell’s lipid structure and releases the _________________ (“emotional brain”) from inhibition.

16. Barbiturates and tranquilizers ____________________ the central nervous system.

17. ____________________ stimulate the central nervous system.

18. ____________________ constricts blood vessels.

19. ____________________ binds to brain receptors, producing a short-term pleasurable feeling.
 

20. ESSAY: What causes withdrawal symptoms?