NEURO 375 SPINAL CORD |43 QUESTIONS AND ANSWERS 2024

How many nerves are in the cervical region? 8 how many nerves are in the thoracic region? 12 how many nerves are in the lumbar region? 5 how many nerves are in the coccygeal region? 1 rostral spinal cord ... is continuous with brainstem caudal spinal cord ends .. at Conus Medullaris (L1/L2) anterolateral sulcus location where ventral roots leave spinal cord (where motor nerves leave the SC) posteriolateral sulcus location where dorsal roots leave spinal cord (where sensory nerves enter the SC) denticuate ligaments extensions of pia, attach pia to dura, provide cord stabilization The C1 nerve is _____ the C1 vertebrae above T12 nerve is _____ T12 vertebrae bellow anterior median fissure a groove along the anterior midline of the spinal cord that incompletely divides it into symmetrical halves conus medullaris sacral part of spinal cord - ends at L1/L2 filum terminale pia mater anchors spinal cord to coccygeal bones what level of the spinal cord does the dural sac end at? S2 how does the white matter of the spinal cord have topography ? - regions designated to ascending axons - regions designated to descending axons regions designated to BOTH ascending and descending axons what SC pathways are ascending 1. fasciculus gracilis 2. fasciculus cutaneous 3. posterior (dorsal) spinocerebellar tract 4. spinothalamic and spinoreticular tracts 5. Anterior (ventral) cerebellar tract what SC pathway(s) both ascend and descend the SC? dorsolateral fasciculus what SC pathways are descending 1. anterior corticospinal tract 2. Lateral (crossed) corticospinal tract (pyramidal tract) why does white matter increase from caudal to rostral SC sections? reflects the level-by-level addition of ascending tracts and the termination of descending tracts cervical and lumbar enlargements greater amounts of grey matter (increased neuronal input and output) What arteries supply the spinal cord? - one anterior artery - two posterior arteries - anastomose with anterior and posterior radicular arteries (from aorta) anterior spinal artery - (one) branch of the vertebral artery - supplies most of the spinal cord - supplies ALL of the SC's grey matter - extends into the anterior median fissure posterior spinal artery - (two) arterial branches from the vertebral artery - supplies the dorsal portion of the SC's grey matter the dorsal and ventral rami of the spinal nerves .. innervate specific regions of the trunk and limbs ventral primary ramus (of T4) anterior branch of a spinal nerve (T4) that innervates the skeletal muscles of the intercostals and abdominals dorsal primary ramus posterior branch of a spinal nerve - (t4) supplies muscle and skin sensation to the back ventral rami supply the antero-lateral parts of the trunk and the limbs (both sensory and motor nerves!!) dorsal rami (of spinal nerves) supply posterior/dorsal body trunk ( skeletal and paravertebral muscles) (both motor and sensory nerves!!) cutaneous branches branches of BOTH dorsal and ventral rami that supply the skin and subcutaneous tissues segmental spinal nerves : spinal nerves that arise from a certain spinal (segmental) level and innervate somatic structures derives from the somites of that SAME level (there are 31)