1. THE NERVOUS SYSTEM

2. The Nervous System Main Functions: - controls & coordinates functions throughout the body - responds to internal and external stimuli Our nervous System allows us to feel pain.

3. The Nervous System Consists of:

4. Nerve: a structure containing a bundle of nerve cells called neurons. Neurons carry electrical messages called impulses throughout the body. This picture shows hundreds of severed neuron axons.

5. PARTS OF A NEURON 1.Cell body: contains nucleus & most of the cytoplasm 2.Dendrites: projections that bring impulses into the neuron to the cell body. 3.Axon: long projection that carries impulses away from cell body 1 3 2

6. Sensory Neuron Interneuron Motor Neuron Sensory Neuron Interneuron Motor Neuron Muscle Contracts Synapse

7. Sensory Neurons carry impulses from sense organs to spinal cord & brain Fun Fact: Where can the largest cells in the world be found? The giraffe’s sensory and motor neurons! Some must bring impulses from the bottom of their legs to their spinal cord several meters away!!

8. Interneuron - connect sensory and motor neurons

9. Motor Motor Neurons carry impulses from the brain & spinal cord to muscles & glands Axons branching out to muscle fibers

10. brain Spinal Cord Cerebellum Cerebrum Medulla Oblongata Consists of: Brain and Spinal Cord

11. Consists of: Sensory division and Motor division - all sensory neurons, motor neurons, and sense organs

12. The Vertebrate Brain in early embryonic stages, all vertebrate brains look similar In weeks three to six, the human embryo will show a backbone, regular heartbeat system and formation of three major brain sections – fore, middle and hind brain.

13. Comparison of Vertebrate Brains all vertebrate brains have the same basic parts, but their relative sizes vary

14. The Vertebrate Brain one major difference between the human brain and other vertebrate brains is the comparative size & structure of the cerebrum The human cerebrum is: 1. more highly developed than in other mammals 2. responsible for movement, sensory processing, olfaction, language and communication, learning and memory

15. Homework Nervous System Worksheet Two – Point Discrimination Lab