KIN 3304 1nd Edition Lecture 10Outline of Last Lecture I. Brief Maximal Tension II. Creating Maximal Tension 1III. Creating Maximal Tension 2IV. Creating Maximal Tension 3V. Isometric/Static TensionOutline of Current 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. Neutral Regeneration Current LectureThese 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.I. Neural Tissuea. 2 Anatomical Divisioni. Central Nervous System1. Brain and spinal cordii. Peripheral Nervous System1. All neural tissue outside the CNSII. CNSa. Brain and Spinal Cordb. Integration, processing, coordinating sensory input, motor outputc. Higher functions as welli. Intelligence, memory, learning, emotionsIII. PNSa. Provides sensory information to CNSb. Carries motor commands from CNS to peripheral tissues and systemsc. 2 Divisionsi. Afferent (information to CNS) – visual commandsii. Efferent (commands to muscle, glands) – actual movementIV. Afferent PNSa. Begins at receptors that monitors environmentb. Receptor may be a:i. Dendrites (sensory process of a neuron)ii. Specialized cell or cluster of cells (ex. muscle)iii. Complex sensory organ (ex. eye)V. Efferent PNSa. Begins inside CNS, ends at an effector b. Both afferent and efferent divisions have somatic sensory receptors…i. Sensory receptors are for conscious control – voluntary)ii. Monitor skeletal muscles, joints, c. … and visceral sensory receptors i. Visceral receptors do not control – ex. breathing, heartbeatii. Monitor internal tissues (smooth cardiac muscle, glandsVI. Components of Efferent Divisiona. Somatic Nervous Systemi. Musclesb. Autonomic Nervous Systemi. Things you don’t control*know diagram of the Central Nervous SystemVII. Astrocytesa. Messengers that send information to the bodyb. Largest, most numerous glial cellsc. Functions:i. Control interstitial environmentii. Maintain blood brain barrier (BBB)1. BBB filters things from coming in and out of brain2. Drug delivery goes through this – caffeine, nicotine iii. Creates 3D framework for CNSiv. Repairs damaged neural tissuev. Guides neuronal developmentVIII. Controlling Interstitial Environmenta. Astrocytes have cytoplasmic processesi. Increases SA of cell1. Allows exchange of ions, molecules with extracellular fluid within CNSii. Processes contact neuronal surfaces1. Isolate neurons from interstitial space within CNS2. Keeps chemical composition from changingIX. Maintaining BBBa. Neural tissue must be isolatedi. Physically and biochemicallyii. Hormones/chemicals in circulation can disrupt endothelial b. Cells lining CNS capillaries have very restrictive permeabilityi. Control chemical exchange between blood into fluidc. BBB isolates CNS from general circulationX. Creates 3D framework for CNSa. Astrocytes have microfilamentsb. Extend across the celli. Reinforcement provides mechanical strengthii. Support neurons of brain, spinal cordc. Ex. building the statue of libertyXI. Repairs Damaged Neural Tissuea. After CNS damage:i. Astrocytes make structural repairsii. Stabilizes tissueiii. Prevents further injury1. Produce scar tissue at injury siteXII. Oligodendrocytesa. Second set of glial cells found within CNSb. Smaller cell bodies, fewer/shorter processesi. Processes tie axon clusters togetherc. Provide myelin sheath in areas of white matteri. kangarood. Maintain cellular organization in gray mattere. Many axons completely sheathed via Oligodendrocytesi. Near tip of process, plasmalemma expandsii. Forms flattened pads that wrap the axon1. Phospholipid bilayerf. Membranous coating called sheathi. Improves (nerve-impulse) speedXIII. Myelin Sheatha. Can form along entire length of axonb. Large, myelinated areas are internodesc. Small gaps exist between sheath produced by adjacent oligosi. Myelin sheath gaps, or nodes of Ranvierii. Loss of myelin  loss of conduction (as in M.S – multiple sclerosis)XIV. Schwann Cellsa. All peripheral neurons covered by Schwann cellsi. Also called neurolemmocytesb. Can myelinate only about 1mm of an axoni. Covering is called neurilemmaii. Oligos can myelinate much moreiii. Functions the same, irrespective of sourcec. Unmyelinated axons are enclosed by processes of Schwann cellsXV. Neurotransmittera. Chemical compound released by 1 neuron to affect the transmembrane potentialof anotherXVI. Signalinga. Message from point A to point B*Know the image of the receptors/PNS/CNS chartXVII. Receptorsa. Exteroceptorsi. External environmentii. Touch, temperature, pressureiii. Sight, smell, auditoryb. Proprioceptorsi. Position/movement of muscles and jointsc. Interoceptorsi. Digestive, respiratory, cardiovascular, etc.ii. Deep pressure and pain, tasteXVIII. Neural Regenerationa. Neurons have limited ability to recover i. After injury, chromatophilic substance disappearsii. If no O2 (stroke) – permanent damage?iii. Cold/nerve injury – permanent damage?b. Wallerian degeneration – disintegration of an axon and its myelin sheath distal toinjury sitei. Axon deterioratesii. Macrophage phagocytize debrisiii. Schwann cells form cord around original