1. BY: CECE GRAFNER, JONELLE GONZALEZ, JASMINE GOWDY, AND ELEANOR MCKNIGHT A PRESENTATION ON THE NERVOUS SYSTEM BRAINS!!!

2. WHAT IS IT? THE NERVOUS SYSTEM System in an animal that coordinates voluntary and involuntary actions. Two main parts Central Nervous System (CNS)= brain and spinal chord Peripheral Nervous System (PNS)= nerves and ganglia (nerve cells and tissue) outside of the brain

4. BRAIN In all vertebrates, and most invertebrates This excludes sponges, jellyfish, sea squirts, and starfish Close to sensory organs vision, hearing, taste, smell, balance Cerebral cortex= largest part connected to 15-33 billion neurons Generates activity through hormones

5. NEURON An electrically excitable cell that processes information through electrical and chemical signals Do not undergo cell division, come from stem cells Connect to form neural networks

6. NEURON CONTINUED.. Sensory neurons= respond to touch, sound, light, and other stuff by sending signals to the brain Motor neurons= cause muscle contractions Interneurons= connect neurons to other neurons within the same region in the nervous system

7. MYELIN A material that forms a layer over the axon of a neuron Regulates the speed of impulses Prevents electrical current from leaving the axon

8. NERVOUS SYSTEM DISORDERS Epilepsy is a seizure disorder caused by spontaneous bursts of disordered electrical activity among nerve cells in the brain. The electrical disturbances provoke seizure activity. Alzheimer's disease is characterized by slowly progressive deterioration of the brain. Buildup and clumping of the brain protein tau interrupts brain cell activity. Eventually brain cells lose their connections with one another and die. Early symptoms of Alzheimer's disease include memory disturbances and decreased capacity for complex thought and planning. As the disease progresses, personality changes occur and motor skills deteriorate

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