1. stimulants - These are substances that increase neural activity in the Central Nervous System that results to increased CNS activity. 2. Amphetamines - Amphetamines activate stress or panic signals that heighten brain activity and also cancels hunger signals. 3. cocaine -Cocaine is a substance derived from the Coca Plant. Dr. Carl Koller in 1884 discovered its anesthetic properties. Its use as a recreational drug started when Arthur Conan Doyle portrayed Sherlock Holmes to use this substance to relieve himself of stress. 4. caffeine - Widely used around the world, caffeine can be found in cacao, coffee beans, and tea leaves. It is a widely unregulated psychoactive drug that prevents drowsiness and stimulates the central nervous system. 5. depressants -This is a substance that reduces the function of the brain and nervous system. This is used to treat anxiety by slowing down alertness, breathing and heart rate. 6. barbiturates - This is a substance that suppresses brain activity by affecting GABA or Aminobutyric acid, a brain neurotransmitter used to send signals within the brain. 7. Tranquilizers - This is a drug mainly used to treat anxiety. Brain activity is reduced by inhibiting dopamine, a neurotransmitter that leads to a reduction of hallucinations, and other psychotic symptoms. 8. Narcotics - This is a substance derived from opium that is known to relieve pain. This substance overcomes the senses and gives the body a sense of relief from pain. The side effect is that it also gives the user a sense of euphoria which is addicting. And that the body builds up resistance to this drug in a matter of days so to continue its use means to introduce increasing amounts in the body.
Answer: The endocrine system plays an important role in homeostasis because hormones regulate the activity of body cells. The release of hormones into the blood is controlled by a stimulus. For example, the stimulus either causes an increase or a decrease in the amount of hormone secreted.
