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The Nervous System. Function. Connects body process to one another Response to stimuli Control of voluntary effectors and mediation of voluntary reflexes. Function. Control of involuntary effectors and mediation of autonomic reflexes
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Function • Connects body process to one another • Response to stimuli • Control of voluntary effectors and mediation of voluntary reflexes.
Function • Control of involuntary effectors and mediation of autonomic reflexes • (heart rate, blood pressure, glandular secretion, etc.) • Responsible for conscious thought and perception, emotions, personality, the mind.
Nervous System Cells • Neurons • Neuroglial Cells • Astrocytes • Microglial Cells • Oligodendrocytes • Ependymal Cells
Astrocytes • Anchor neurons to blood vessels. • Transport nutrients • Part of “blood-brain barrier”
Microglial Cells • Phagocytic cells to defend against pathogens • Remove damaged brain cells
Oligodendrocytes • Provide myelin layer in Central Nervous System only • Myelin layer is provided by Schwann cells in Peripheral Nervous System
Ependymal Cells • “Epithelia-like” • Line fluid filled cavities of the brain and spinal cord.
Review • Identify what you think was the most fundamental information that was just covered • Identify what you think was the most confusing or challenging information that was just covered
Review • Turn and talk with your neighbor • Knees pointing at each other • Eye contact • Actively listen to your neighbor • Address any questions or concerns he/she may have as best you can • Ask teacher about any unanswered questions
Resting Potential • Resting Neuron – one that is not transmitting an impulse. • Polarized – slight positive charge outside the cell membrane, negative charge inside the cell. • http://www.youtube.com/watch?v=YP_P6bYvEjE&feature=relmfu
Generating an Impulse • Resting Potential – The difference between the charge outside the cell and inside the cell • Threshold Level – The level of charge needed to trigger an impulse
Dendrites • Receptors on dendrites are triggered
Dendrites • Impulse is sent from the dendrites to the cell body
Action Potential • Resting Potential • Equilibrium of K+ ions and a slight negative charge inside the cell
Action Potential • Depolarization • Threshold is reached and Na+ channels open • Na+ ions diffuse in causing a positive charge in the cell
Action Potential • Na+ ions diffuse down the axon, triggering Na+ channels to open
Action Potential • Repolarization • Na+ channels close and K+ channels open • K+ ions diffuse out of the cell, reducing the positive charge
Action Potential • Hyperpolarization • Too many K+ ions diffuse out of cell • Action potential can not be generated • K+/Na+ pump restores equilibrium • http://www.youtube.com/watch?v=U0NpTdge3aw&feature=related • http://www.youtube.com/watch?v=7EyhsOewnH4&feature=related
Myelin Sheath • Myelin insulates positive charge allowing it to travel further and faster
Review • Identify the one, most important, concept that a person needs to know about an action potential. • Identify a concept about an action potential that a person may get confused about
Review • Turn and talk with your neighbor • Knees pointing at each other • Eye contact • Actively listen to your neighbor • Address any questions or concerns he/she may have as best you can • Ask teacher about any unanswered questions
Synapse • Action Potential reaches the axon terminal • Neurotransmitters released from synaptic vesicles • http://www.youtube.com/watch?v=LT3VKAr4roo&feature=related
Neurotransmitter Signal • Excitatory • Trigger threshold event • Inhibitory • Inhibit threshold event
Neurotransmitters • Acetylcholine (+) • Stimulate muscle contractions • Monoamine • Epinephrine(+) • Dopamine(-) • Serotonin(-) • Histamine(+) • Amino Acids • Glycine • GABA(-) • Aspartic acid • Neuropeptides • Endorphins • Enkephalins
Ending Transmission • Decomposed by enzymes • Reuptake – reabsorbed by synaptic knob
Nervous System Flow Chart Draw a flow chart that organizes the nervous system. Use and define the following key words (in your own words). Illustrate each keyword with an image, be creative. This is a individual assignment. • Nervous System • Neurons • Internuerons • Motor Neurons • Sensory Neurons • Central Nervous System • Peripheral Nervous System • Somatic Nervous System • Reflex • Autonomic Nervous System • Sympathetic Nervous System • Parasympathetic Nervous System