NERVOUS SYSTEM• Interpreting, processing and transferring information
Across Species• Lets look at some different organisms and how their nervous system is oriented.• Try to focus on structure and function… What the organism looks like, where/how it lives
Simple Centralized GastrovascularOrganism cavity. Noonly a few complex methodcells thick to deliver ions for nervous system Simple Organism…Sessile NO need for complex skeletal Simple nervous movements system
Can learn to Ganglia: Group of change responsesnervous tissue Due to stimuliCephalizationEyespots to Slightly moresense light complex organism…and detect with a slightly more specific complex Nervous system chemicals
Larger morecomplex organism than the Primitive Planarian… More complex system Brain Multiple Ganglia throughoutbody for more complexresponses and coordination
Larger more complex organism…Larger more complex system Developed sensory organs Must have a more developed LARGE Axonsextending from system to process brain tissue information
Molecular Components of Neural CommunicationNEURON: a cell of the nervous system
PARTS OF A NEURON• Cell Body : Nucleus and Organelles of the neuron… if it dies the neuron dies… FOREVER• Axon: The SENDING end of a neuron – Axon hillock: Signal generation site of an axon – Synaptic Terminals: Where neurotransmitters are stored and expelled into the synapse• Dendrites: The RECEIVING end of a neuron• Synapse: The space between communicating neurons
Details of a Nervous Signal• Nervous system connects all body systems and functions with ion exchanges and neurotransmitters to make its point
NEUROTRANSMITTERS Released by the PRESYNAPTIC cell to cause an affect on the POSTSYNAPTIC cell• Acetylcholine: Most studied in the muscular response, but also in Memory formation and learning. Causes an excitatory response in muscle cell. Homeostasis… feedback• Acetyl cholinesterase hydrolyzes Acetylcholine terminating the excitatory response. Otherwise your muscles would Contact out of control!!!
Botox is aQUESTION prevents neurotoxin that vesicles containing acetylcholine from being released into the• If I told you BOTOX was a neurotoxin that synapse. The vesicles are unable to disrupted the function of Acetylcholine… connect to the cell membrane to WHAT DOES THAT MEAN??? release their contents Ach cannot cause a contraction of The muscle. Muscles relax and wrinkles fade. And EYEBROWS do not move for 3-4 months!
DOPAMINE and SEROTONIN• Made from amino Acids• Affect sleep, mood, attention and learning• Treat depression by inhibiting the reabsorption of Serotonin allowing it to remain in the synapse longer… PROZAC more serotonin to react, more HAPPY• Lack of Dopamine in the brain is associated with Parkinson’s disease… a degenerative nerve disease associated with a lack of muscle control LSD & L-dopa (derivative) can doc with the VIDEO ATTACHED! dopamine receptors
Click boy PAIN Neurotransmitters• Substance P (a neuropeptide)- “P FOR PAIN!” This neurotransmitter allows you to feel PAIN! Nocieptors- dendrites that receive noxiousthermal, mechanical or chemical PAINinformation.• Endorphins – This neurotransmitter diminishes pain. – Opiate, Morphine and heroin mimic Endorphins… Similar shape, can doc with the endorphin receptor to cause euphoria. They also increase urine output.
THINKING IT THROUGH• You have now had several examples of different neurotransmitters and their function in the body.• Take a moment to discuss how some medicines are made. Be sure to document your answer in your notes
NERVOUS SYSTEM organization1. Central nervous system a. Brain : Processing center b. Spinal cord : sending and receiving 2. Peripheral nervous system a. Somatic (Motor) : voluntary (except REFLEX) b. Autonomic : involuntary
How is this regulation AUTONOMIC NS • The Autonomic nervous system is further Efficient? divided into Sympathetic and Parasympathetic What do you notice about the relationship between the 2 divisions? Which one would be activated when you are being chased by the Boogie man
AUTONOMIC NS• The 3rd division: Enteric – Control of smooth muscles (digestion), Cardiac muscles and glands
HOW is a reflex efficient? HOW is it protective?
Synapse Nociceptor WHY THIS DIAGRAM IS MISLEADING OUCH! Sensory neuron EFFICENT 1. Interneuron are 2. The sensory neuronCross Section of REGULATION! One Spinal cord primarily INHIBITORY ALSO sends a message stimulus… 2 to the brain…thejust responses… It They inhibit theSAME takes longer… which is sensory nerve can antagonistic muscle group. Interneuron why there is aone muscle stimulate second or twowhile inhibiting the that your burn other! doesn’t hurt Take a moment to describe the Interneurons typically release neurotransmitter Muscle GABA… which is Motor Neuron inhibitory what happens in a reflex in contraction your notes