Test 2 Study Guide

Test 2 Study Guide - The brain Nervous system pathways...

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The brain Nervous system pathways (afferent vs. efferent) Afferent nerves o Sensory nerves – skin to brain communication Efferent nerves – motor nerves - take info from brain down to body (muscles) Nervous system divisions: what they are and what they do Central Nervous System (CNS) o The brain and spinal cord, those parts of the nervous system that are encased by the skull and vertebrate bones Peripheral Nervous System (PNS) o Somatic Nervous System – sensory neurons and motor neurons Autonomic nervous system – control internal organs and glands, controls automatic functioning Sympathetic Nervous System – activates us (fight or flight) Parasympathetic nervous system – calms us after activation o Parts of the nervous system that connect the brain and spinal cord to the rest of the body including: Sensory connections to sensory receptors in the skin Motor connections to body muscles Autonomic connections to body organs Nervous system cells: neurons and glial cells Neurons o Nerves and tracts o Cells that make up the nervous system Nerve o Bundle of neurons going through the body Tract o Bundle of neurons in the brain Astrocytes o Provide blood to neurons o Feed Neurons Schwann cells and Oligodendrocytes o Wrap around neurons o Provide myelin sheath to neuron
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Parts of a neuron and what they do Neural impulse: explain how it works, importance of myelin sheath, all-or-none law Neural Impulse o Action Potential Traveling electrical charge down the axon o Resting Potential Polarization (-70 millivolts) Sodium-potassium pump: moves 3 Na+ ions out for every 2 K+ ions that enter Steps in neural impulse o Messages from other neurons Excitatory (Na+ ions move in) Inhibitory (Cl- ions move in) Threshold (approximately -55 mV) If pass threshold, get start of action potential if enough sodium ions get in – once the inside of the cell reaches -55 mV we get the start of our action potential (neuron is going to fire) o Depolarization at base of axon Many Na+ channels open briefly Na+ channels close, K+ channels open K+ leaves cell Back to resting potential (-70 mV)
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K+ channels close Sodium-potassium pump restores order in that one area (K+ in and Na+ out) Neural impulse o Na+ inside axon makes the next area pass the threshold and “fire” Action potential travels down axon All or none law o the axon or fires or does not fire Importance of myelin sheath o insulator, speeds neural impulse Neural communication: explain how it works, synaptic development and change Neural Communication o Its Chemical o Synapse two neurons meet and communicate Pre- and Post- synaptic neurons Flexibility of receptors “regulation” Synaptic charge and development o Synaptic vesicles chemicals inside of them, bind to membrane, release chemicals into synaptic cleft, chemicals bind to receptors in dendrite
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This note was uploaded on 04/24/2008 for the course PSYC 100 taught by Professor Madigan during the Spring '07 term at USC.

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Test 2 Study Guide - The brain Nervous system pathways...

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