1. Brain

2. Brain Anatomy The brain consists of several large regions each responsible for some of the activities vital for living.

3. These include:  Brain stem- controls basic functions critical to life such as heart rate & breathing  Limbic System- contains brain’s reward circuit  Cerebral Cortex- divided into areas that control specific functions such as see, feel, hear & taste.

4. Neuron- nerve cells of the brain Parts of a Neuron Axon- a fiber that sends messages to other neurons Dendrites- the branching structure of a neuron that messages Dendrites- the branching structure of a neuron that helps conduct messages

5. Parts of a Neuron, cont. Nucleus- directs all of the cell activity Synapse- gap between the axon & dendrite. Neurotransmitters cross it Receptor site- molecule that receives the neurotransmitter once it crosses the synapse

6. The average Weighs 3 lbs

7. Nerve cells and Neurotransmission The brain is made up of billions of nerve cells. Most neurons contain three parts – dendrites, axon and central cell body. The transfer of a message from axon to another is called neurotransmission Communication between nerve cells occurs through the release of chemicals into the space between axon and dendrite. This space is called the synapse.

8. When neurons communicate, a message, traveling as an electrical impulse, moves down an axon toward the synapse. There it triggers the release of molecules called neurotransmitters from the axon into the synapse. The neurotransmitters then extend across the synapse to bind to special molecules, called receptors, within the cell membrane of the next nerve cell. This stimulates or inhibits an electrical response in the receiving neuron’s dendrites. Thus, the neurotransmitters act as chemical messengers, carrying information from one neuron to another.

9. How Does the Brain Communicate? 1. Neuron to neuron-Each nerve cell sends & receives messages in forms of electrical impulses 2. Neurotransmitters- Brain’s Chemical Messengers- The messages are carried between neurons by chemicals called neurotransmitters 3. Receptors- Brain’s chemical “Receivers” the neurotransmitter (chemical) attaches to the receptor. 4. Transporters- Recycles the neurotransmitters

10. Neuron-Picture

11. Interesting Facts…. Average number of neurons in the human brain -100 billion Average number of neurons in an octupus’ brain =300 billion Rate of neuron growth during fetal development= 25,000/minute Longest axon of a neuron= around 15 feet (Giraffe’s primary afferent axon from head to toe

12. 1) Schedule I. - (A) The drug or other substance has a high potential for abuse. (B) The drug or other substance has no currently accepted medical use in treatment in the United States. (C) There is a lack of accepted safety for use of the drug or other substance under medical supervision. (2) Schedule II. - (A) The drug or other substance has a high potential for abuse. (B) The drug or other substance has a currently accepted medical use in treatment in the United States or a currently accepted medical use with severe restrictions. (C) Abuse of the drug or other substances may lead to severe psychological or physical dependence. (3) Schedule III. - (A) The drug or other substance has a potential for abuse less than the drugs or other substances in schedules I and II. (B) The drug or other substance has a currently accepted medical use in treatment in the United States. (C) Abuse of the drug or other substance may lead to moderate or low physical dependence or high psychologicaldependence. (4) Schedule IV. - (A) The drug or other substance has a low potential for abuse relative to the drugs or other substances in schedule III. (B) The drug or other substance has a currently accepted medical use in treatment in the United States. (C) Abuse of the drug or other substance may lead to limited physical dependence or psychological dependence relative to the drugs or other substances in schedule III. (5) Schedule V. - (A) The drug or other substance has a low potential for abuse relative to the drugs or other substances in schedule IV. (B) The drug or other substance has a currently accepted medical use in treatment in the United States. (C) Abuse of the drug or other substance may lead to limited physical dependence or psychological dependence relative to the drugs or other substances in schedule IV. (c) Initial schedules of controlled substances Schedules I, II, III, IV, and V shall, unless and until amended (FOOTNOTE 1) pursuant to section 811 of this title, consist of the following drugs or other substances, by whatever official name, common or usual name, chemical name, or brand name designated: (FOOTNOTE 1) Revised schedules are published in the Code of Federal Regulations, Part 1308 of Title 21, Food and Drugs. 811

15. Parts of a Neuron, cont. Cell Body- the body of the neuron that contains the nucleus Nucleus- the organelle in the cell body that contains the genetic material of the cell.

16. Parts of a Neuron, cont. Receptor site- a protein that binds to a specific molecule such as a neurotransmitter or other substance and initiates a cellular response.