Chapter 12 Spinal Cord Review Sheet PDF

Chapter 12 Spinal cord review sheet 1) Extends from foreman magnum to L1 or L2 2) Pia, arachnoid, and dura mater; dura and arachnoid extend past spinal cord to the sacrum; lumbar puncture 3) Epidural space 4) Cervical and lumbar enlargements 5) Conus medulliaris, filum termina...

Chapter 12 Spinal cord review sheet 1) Extends from foreman magnum to L1 or L2 2) Pia, arachnoid, and dura mater; dura and arachnoid extend past spinal cord to the sacrum; lumbar puncture 3) Epidural space 4) Cervical and lumbar enlargements 5) Conus medulliaris, filum terminae, cauda equina 6) 31 pairs of spinal nerves, C1-C8, T1-T12, L1-L5, S1-S5, Co1 7) C1-C7 nerves are above the corresponding vertebra (e.g. C2 nerves are above C2 (axis)). 8) C8 is above the T1 vertebra 9) T1-T12 and L1-L5 are all below the corresponding vertebra 10) Spinal cord segments are named for the associated spinal nerves. In lower segments, spinal cord segments are NOT aligned with the corresponding vertebra. Vertebral column is longer than the spinal cord. E.g. L5 spinal cord segment is superior to the L5 vertebra (spinal cord does not extend past L1 or L2). 11) Central canal with CSF 12) Dorsal horns: interneurons that receive somatic and visceral sensory input 13) Ventral horns: some interneurons; somatic motor neurons 14) Lateral horns (only in thoracic and superior lumbar regions): sympathetic neurons 15) Gray commissure: bridge of gray matter that connects masses of gray matter on either side 16) Encloses central canal 17) Ventral roots: bundle of motor neuron axons that exit the spinal cord 18) Dorsal roots: sensory input to cord 19) Dorsal root (spinal) ganglia: cell bodies of sensory neurons 20) Spinal nerves: formed by fusion of dorsal and ventral roots 21) White matter: ascending, descending, transverse (information highway of spinal cord) 22) Paresthesias: caused by damage to dorsal roots or sensory tracts a. Leads to sensory function loss 23) Paralysis: caused by damage to ventral roots or ventral horn cells a. Leads to motor function loss b. Two types of paralysis: flaccid or spastic 24) Ascending pathways: a. 1st order neuron: sensory receptor to spinal cord or medulla b. 2nd order neuron: spinal cord or medulla to thalamus or cerebellum (unconscious proprioreception) c. 3rd order neuron: thalamus to cerebral cortex 25) Descending pathways: a. Direct motor pathways initiate movement while indirect motor pathways terminate movement. This fine tunes motor activity. Direct pathways are analogous to the gas pedal while indirect pathways are like brakes. Precise control of muscles requires both. b.