General - Starts at foramen magnumWhere? – down in vertebral column(14.2) Meninges/membrane? – Dura mater/arachnoid/pia materVertebral foramenSpinal nerves – left and right nerve exits between each pair of vertebraCross section (14.4)Anterior/ posterior hornsGray commissureConnects left and right horns. A bridge.Spinal=central canalIn the middle of the commissure, gives CSF to spinal cordAnterior median fissureAnterior.Posterior median sulcusPosterior.White matter > funiculi = columnsPosterior, anterior, lateral “columns”… defined by the horns of gray matter.Spinal nerve rootsPosterior root = dorsal root (swelled up with gray matter)GanglionAnterior root = posterior rootTracts: (15.2/15.5)Ascending (afferent/in) – sensoryDescending (efferent/out) – motor/muscle commandsSpinal cord segments and spinal nervesCervicals – 8 (c1-c8)one extra spinal nervec1 comes out on top of c1 vertebrae, c8 nerve comes out below c8 vertebraeThoracics - 12Lumbars - 5Sacrals - 5Growth – spinal cord vs vertebral columnLengthDoes not grow much. Out grows the spinal cord. Spinal column grows a lot.The nerves roots grow long enough to keep up with the growthCauda equina – bundle of nerves at the end of the vertebral column/spinal cordPathways of signals in the spinal cord (14.16)spinal reflexes – behavior controlled by spinal cordreflex arc – route from the sensor, to the muscle. (signal pathway)simplest / monosynaptic – knee jerk (stretch reflex)rubber hammer and wack patellar ligament. Causes the spinaspinal cord 03/31/2014General - Starts at foramen magnumWhere? – down in vertebral column (14.2) Meninges/membrane? – Dura mater/arachnoid/pia mater Vertebral foramen -Spinal nerves – left and right nerve exits between each pair of vertebra Cross section (14.4)-Anterior/ posterior horns-Gray commissure oConnects left and right horns. A bridge. -Spinal=central canaloIn the middle of the commissure, gives CSF to spinal cord-Anterior median fissureoAnterior. -Posterior median sulcusoPosterior.-White matter > funiculi = columns oPosterior, anterior, lateral “columns”… defined by the horns ofgray matter. -Spinal nerve rootsoPosterior root = dorsal root (swelled up with gray matter)oGanglion oAnterior root = posterior root Tracts: (15.2/15.5)-Ascending (afferent/in) – sensory -Descending (efferent/out) – motor/muscle commands Spinal cord segments and spinal nerves -Cervicals – 8 (c1-c8)oone extra spinal nerveoc1 comes out on top of c1 vertebrae, c8 nerve comes out below c8 vertebrae -Thoracics - 12-Lumbars - 5-Sacrals - 5Growth – spinal cord vs vertebral column -LengthoDoes not grow much. Out grows the spinal cord. Spinal column grows a lot. oThe nerves roots grow long enough to keep up with the growth-Cauda equina – bundle of nerves at the end of the vertebral column/spinal cord Pathways of signals in the spinal cord (14.16) -spinal reflexes – behavior controlled by spinal cord-reflex arc – route from the sensor, to the muscle. (signal pathway)-simplest / monosynaptic – knee jerk (stretch reflex)orubber hammer and wack patellar ligament. Causes the