KIN 3304 1nd Edition Lecture 11Outline of Last Lecture I. Neural TissueII. CNSIII. PNSIV. Afferent PNSV. Efferent PNSVI. Components of Efferent DivisionVII. AstrocytesVIII. Controlling Interstitial EnvironmentIX. Maintaining BBBX. Creates 3D framework for CNSXI. Repairs Damaged Neural TissueXII. OligodendrocytesXIII. Myelin SheathXIV. Schwann CellsXV. NeurotransmitterXVI. SignalingXVII. ReceptorsXVIII. Neural Regeneration Outline of Current Lecture I. Neural Regeneration cont.II. Rate of Nerve ImpulseIII. Types of Processing IV. Aging and Nervous SystemV. Changes in AgedVI. Subdivisions of ANSVII. Sympathetic StimulationVIII. When Activation Occurs…Current LectureI. Neural Regeneration cont.a. Schwann cells release growth factorsi. Promote axonal regrowthThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.ii. If axon cut – new axons may emerge at cut within hoursiii. Most likely – at site of injury, axon dies, regenerates1. New axonal segments sprout 1 week later2. As neuron recovers, axon growsII. Rate of Nerve Impulsea. Depends on proportion of the axonb. 1. Presence of myelin sheathi. Myelinated axon conducts 5-7x fasterc. 2. Diameter of axoni. large diameter = more rapid impulseii. 140 m/s (300 mph)III. Types of Processing (KNOW THIS)a. Divergence info spreads from one to multipleb. Serial Processing occurs as sensory information is relayed from one center to another in the brainc. Parallel Processing occurs when several neurons or pools process same information at the same timei. Allows for reflexesd. Reverberation allows neurons to remain active once they are stimulatedi. Once active, will continue until synaptic fatigue or inhibitory stimuli breaks cycle1. Think of breathing: must inhibit this from occurring*TQ: FIGURE 16.6 – the exact picture. Know the white part!IV. Aging and Nervous Systema. Reduced in brain weight/sizeb. Reduced in neuronsc. Decreased blood flow to braind. Changes in synaptic organization of braine. Cellular changes in CNS neuronsV. Changes in Ageda. Reduced in brain weight/sizei. Results primarily from decrease in volume at cerebral cortexb. Reduced in number of neuronsi. Reduced brain size linked to loss of cortical neuronsc. Decreased blood flow to braini. Fatty deposits occur in walls of blood vesselsii. This decreases articular flow1. Increases stroke riskiii. Called atherosclerosisd. Changes in synaptic organization of braini. Number of dendric branches and interconnections decreaseii. As synaptic connections lost, rate of neurotransmitter production declinese. Intracellular /extracellular changes in CNS neuronsi. Neurons in brain accumulate abnormal depositsii. Plaques form extracellularly1. Amyloid (fibrillar protein)2. Surrounded by abnormal dendrites/axonsiii. Neurofibrillary tangles1. Mass of neurofibrils2. Form dense mats inside soma*KNOW Fig 17.1 – how things flow on the left.VI. Subdivisions of ANSa. 2 Major Subdivisionsi. Sympathetic and Parasympatheticii. In general1. Parasympathetic dominates at rest2. Sympathetic dominates during stressiii. Excitation and inhibition, respectivelyiv. But not always1. Divisions may work independently2. May work togetherVII. Sympathetic Stimulationa. Can change organ/tissue activities by releasing catecholamines (epi, norepi) in blood streamb. Activated in reflexes that do not involve other effectorsc. Sympathetic activation (entire division response) controlled by sympathetic centers in hypothalamusVIII. When Activation Occurs…a. Increase alertness (stimulation of reticular activating system); now “on edge”b. Insensitive to painful stimuli, increase energyc. Increase cardiovascular and respiratory center activityi. Increase in strength, HR, BP, respiration rate/depthii. Hyperventilating d. Increase muscle tone (looks tense) – shiverse. Mobilization of energy reservesi. Increase breakdown of
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