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Topic : Nervous System Aim : Describe the structure of nerve cells and how an impulse travels through them. Do Now : You are sound asleep and a loud alarm clock goes
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Topic: Nervous System Aim: Describe the structure of nerve cells and how an impulse travels through them. Do Now: You are sound asleep and a loud alarm clock goes off…you wake up. Identify the stimulus, receptor, effector and response HW: Read p. 596. Make recall notes about the three types of neurons.
Did you know... There are millions of nerve cells in the human body. This number even exceeds the number of stars in the Milky Way. The nervous system is very quick, it can transmit impulses at a tremendous speed of 100 meters per second. The speed of message transmission to the brain can be as high as 180 miles per hour. Neurons, which are the largest cells in the human body, do not undergo the process of mitosis.
Neuron Nerve Cell
Parts of neuron 1. Dendrites: receive impulse 2. Cell body / cyton: contains nucleus 3. Axon: carries impulse away from cell body 4. Terminal branches: send impulse to next neuron
Did you know: The longest axon of a neuron is approximately around 15 feet (Giraffe primary afferent axon from toe to neck)
Synapse Space bw neurons
dendrite muscle tissue Axon cell body TYPICAL MOTOR NEURON synapse Impulse in a Neuron cell body
Neurotransmitters released into the synapse Attach to receptors on next neuron http://www.youtube.com/watch?v=z3F5dfmQ3hk&feature=related
http://www.youtube.com/watch?v=haNoq8UbSyc&NR=1&feature=endscreenhttp://www.youtube.com/watch?v=haNoq8UbSyc&NR=1&feature=endscreen
Let’s summarize… • What are nerve cells called? • Identify the four parts of a neuron. • Which part of the neuron receives the impulse? • Identify the long part of the neuron. • Which part of the neuron helps send the impulse to the next neuron? • What is the space between 2 neurons called? • Identify the chemical that is secreted into the space. • Identify the structures that this chemical will attach to on the next neuron.
Review: Identify the part of the neuron being described. Long part of neuron that carries the impulse to the terminal branches. First part of the neuron that receives the impulse. Release neurotransmitters. Contains the nucleus. Helps the impulse travel faster. The space in between two neurons.