1. The Nervous System
-The nervous system controls and coordinates functions throughout the body.
-The basic units of the nervous system are neurons.

2. The Neuron

3. Cell Body (soma)- contains the nucleus and much of the cytoplasm.
2. Nucleus- contains genetic material, directs cellular activity.
3. Dendrites- short branched extensions off the cell body. Carry impulses from the environment or other neurons toward the cell body.

4. Axon- long fiber that carries impulses away from the cell body.
Nodes of Ranvier- gaps between Schwann Cells.
Myelin Sheath- insulating membrane that surrounds the axon.

5. Schwann Cell- wrap around the axon.
Terminal Branches- end of the nerve cell, send messages out into the synapse (space between neurons).
Synaptic Knobs- release neurotransmitter into the synapse.

6. The Synapse

7. The impulse reaches an axon terminal or synaptic knob.
Knob contains tiny sacs (vesicles) that are filled with neurotransmitters.
Neurotransmitters diffuse across the gap and attach to receptors on the membrane of the neighboring cell, and the impulse is transmitted.
Drugs and the brain

8. Three types of Neurons Sensory neurons:
Located in the sense organs (eyes, ears, nose, tongue, and skin)
Transmit impulses from receptors to the brain and spinal cord.

9. Interneurons: Located in the brain and spinal cord.
Intepret and relay messages between sensory and motor neurons.

10. Motor neurons:
Transmit impulses from the brain and spinal cord to muscles and glands (effectors).

11. Spinal Cord Center for reflex action. What is a reflex?
Quick, automatic response to a stimulus.
Allows your body to respond to danger immediately.

12. Reflex Arc:
Receptorsensory neuron interneuron(in the spinal cord)motor neuroneffector (muscle or gland)
reflex arc animation

17. What color is each word in?

18. The Central Nervous System
Includes the brain and spinal cord.

19. The Brain Large mass of neurons in the cranial cavity.
Includes three major divisions each having specialized functions.

21. 1. Cerebrum Center for voluntary activity.
Memory, thinking and reasoning occur.

22. 2. Cerebellum
Coordinates motor activities and aids in maintaining balance.

23. 3. Medulla
Controls involuntary activities such as breathing, heartbeat, blood pressure and peristalsis.

26. Malfunctions of the Nervous System
Meningitis- inflammation of the membranes surrounding the brain and spinal cord.
Stroke-A stroke happens when blood flow to a part of the brain stops. A stroke is sometimes called a "brain attack."