NSC 4366 1st Edition Lecture 4 Outline of Last Lecture I Neurologic Imagine a x ray b CT c MRI d PET e Cerebral Angiography Outline of Current Lecture II External anatomy of the spinal cord III Cross sections a Spinal Nerves IV Pathways Current Lecture the spinal cord starts as a flat plate It rolls up into a tube to form the spinal cord The spinal cord and its spinal nerves receive fibers from sensory receptors of body control movements of trunk and limbs provide autonomic innervation for the viscera the altar plate contains mostly sensory neurons the basal plate at the bottom contains motor neurons The external anatomy of a spinal cord spinal cord lies in the vertebral column which provides support and protection These 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 the denticulate ligament looks like teeth they attach the spinal cord to the side hold down the spinal cord laterally Most important for this class fat in epidural space cushions the spinal cord rami will not be on test dorsal root ganglion looks pregnant because it s a collection of cell bodies The dorsal root ganglion is sensory Hornsdorsal and ventral horns are large at cervical and lumbar levels due to intervention of upper and lower limbs anterior horn cell bodies Cervical and Lumbar are larger because they contain cell bodies for motor neurons The image below is important for safely knowing where to place a spinal tap You want to place the needle through the fat passed the dura and into the subarachnoid space Trying to avoid the Corus Medlaris the end of the spinal cord You want to place the spinal tap below Cauda equina because if you damage a nerve it can heal but if you damage the spinal cord it can t heal The ideal place to put the needle is in L3 Growth of vertebral column exceeds that of spinal cord spinal cord rises over time at birth the cord ends at L3 in adults between L1 and L2 Tethered cord release sometimes the spinal cord can t rise because the tether is preventing it from rising Tethered cord can cause paralysis Stretched spinal cords cause things to rip and break Reflexes increase because of motor pathways are increased Fassicles groups of fascicles from each cord segment coalesce to form dorsal and ventral nerve roots They coalesce to bind together Internal structure of spinal cord Anterior median fissure is in ventral cord Fissure small crack You should know the internal structure of the spinal cord for the practicum image below White matter fiber tracts are on the outside blue Gray matter neuronal cell bodies are on the inside If stabbed in the back in the dorsal side complain of sensory problems first If stabbed in ventral side complain of motor problems Tracts to Know on left hand side sensory on right hand side lateral corticospinal tract motor Coricospinal pathway goes from cortex to spine which makes it motor Spinocerebellar from spine to cerebellum sensory Spinothalamic tract pain pathway MEMORIZE substantia gelatinosa is a cell body This is where pain comes from nucleus proprius nucleus for the proper system touch vibration Dorsal horn Input zone Ventral horn output zone Cell bodies live here in the red zone ex polio kills cells right here Light touch sensory fibers go down to the ventral cord to communicate with the motor system If someone had a lesion in the Substantia gelatinosa they would not feel pain Dorsal root ganglion is outside of the blood brain barrier so it can be attacked Pain fibers in red non pain in black Pain fibers in red non pain in black proprioception when you can feel if your hand is facing up or down happens in the black pathways Unconscious proprioception cerebellum isn t in consciousness The pathways don t cross Ex liver changes its size hour by hour but you don t feel it The cerebellum feels it but you don t The cerebellum says no reason to tell the brain about this I ll take care of it and that s why you don t feel it Lateral Horn present in middle lumbar region possess cell bodies of the sympathetic nervous system This is how the brain talks to and activates the sympathetic nervous system through the lateral horn in the lumbar region Chronic pain is maintained by the activation of the sympathetic nervous system Sometimes surgeons cut this region out completely to resolve chronic pain