Presentation on theme: "AP Biology 2003-2004 Nervous System Regents Biology 2003-2004 Why do animals need a nervous system? What characteristics do animals need in a nervous."— Presentation transcript:
Regents Biology 2003-2004 Why do animals need a nervous system? What characteristics do animals need in a nervous system? fast accurate reset quickly Remember… think about the bunny… Poor bunny!
Regents Biology 2003-2004 Nervous System Central nervous system brain & spinal chord Peripheral nervous system nerves from senses nerves to muscles cerebrum cerebellum spinal cord cervical nerves thoracic nerves lumbar nerves femoral nerve sciatic nerve tibial nerve
Regents Biology 2003-2004 Nervous system cells dendrites cell body axon synapse Neuron a nerve cell signal direction signal direction
Regents Biology 2003-2004 Fun facts about neurons Most specialized cell in animals Longest cell blue whale neuron 10-30 meters giraffe axon 5 meters human neuron 1-2 meters Nervous system allows for 1 millisecond response time
Regents Biology 2003-2004 Myelin sheath signal direction Axon coated with insulation made of myelin cells speeds signal signal hops from node to node 330 mph vs. 11 mph myelin sheath Multiple Sclerosis immune system (T cells) attacks myelin sheath loss of signal Multiple Sclerosis immune system (T cells) attacks myelin sheath loss of signal
Regents Biology 2003-2004 Synapse Junction between nerve cells 1st cell releases chemical to trigger next cell this is where drugs affect nervous system
Regents Biology 2003-2004 Types of neurons sensory neuron (from senses) interneuron (brain & spinal chord) motor neuron (to muscle)