Lesson 4 neurotransmission and reflex arc NS.notebook May 16, 2017 Aim: Explain how neurotransmission work and how impulse travels in the reflex arc? Hw. Finish worksheet distributed in class. Do all multiple choice questions (section A) 2nd practice regents UPCOs book. 1. Quiz 2. Review the anatomy of a neuron 3. Neurotransmission 4. Synapses Video and explanation. 5. The reflex arch to illustrate how the N. S. responds to stimuli. 6. worksheet. ß May 13­2:15 PM 1. Neurons: • The cells of the N. S. are called neurons • Neurons are cells specialized in carrying electrical impulses. (Draw and label) May 12­10:56 PM 1 Lesson 4 neurotransmission and reflex arc NS.notebook May 16, 2017 2. The process of neurotransmission • Neurons create an action potential or electric impulse (by using active transport of Na+ and K+ create an electric change) in response to stimuli • The action potential travels in one direction only from dendrites to axon terminals http://highered.mheducation.com/sites/0072495855/student_view0/chapter14/ animation__the_nerve_impulse.html • Neurons are not physically connected there is a space between them. Called synaptic space. May 12­3:00 PM 3. Synapses (wathch the video and after explain the steps using your own words) https://www.youtube.com/watch?v=p5zFgT4aofA The action potential causes the axon terminal to release stored chemicals (neurotransmitter) into the space between neurons Synapses occurs when neurotransmitters(molecules) bind to receptors in surrounding dendrites and trigger an action potential . May 16­12:19 PM 2 Lesson 4 neurotransmission and reflex arc NS.notebook May 16, 2017 4. The reflex arc: (Explain the process describe it in your own words) https://www.youtube.com/watch?v=c­dD0N53QRg The reflex arc is a complete circuit that produces an involuntary response. It works as follows: 1· sensory receptors in sensory organs pick up a stimulus in the environment. 2. it initiates an action potential in a sensory neuron 3. The impulse reaches interneurons in the Spinal cord. • 4 The interneurons there, process the message and form a response. 5. · The response travels through the motor neurons. connected to a muscle ﴿or gland ﴾effector 6. The effector executes the action. All the actions of the autonomic N. S. are controlled by 2 subsystems with opposite effects. The sympathetic N. S. Increases a response The Parasympathetic N. S. decreases the response. May 13­3:07 PM Comparison of endocrine and Nervous systems. The nervous system The endocrine system • uses action potentials * uses hormones (electrical impulses) (chemical messengers) • Made of Neurons 3 *made of Glands kinds (S.>I.>M.) Hormones target particular tissues (because the tissue has the receptor for that particular Hormone) • Fast immediate action * Slow and long lasting action or effect May 12­7:37 AM 3 Lesson 4 neurotransmission and reflex arc NS.notebook May 16, 2017 May 15­2:17 PM May 14­10:21 AM 4.