Spinal cord anatomy Flashcards
Afferent nerve fiber
carry info from sensory receptors in skin to CNS
Efferent motor fibers
carry info from CNS to periphery
Spinal Rootlets
thin bundles of afferent and efferent fibers/axons
Spinal Root
groups of rootlets that converge. Dorsal root is sensory and ventral root is motor
Spinal Nerve
union of dorsal and ventral root
Spinal segment
region between two groups of rootlets
How many pairs of spinal nerves emerge from spinal cord? Where do they come from?
31 total. 8 cervical, 12 thoracic, 5 lumbar, 1 coccygeal
Which cranial nerves emerge from the brainstem?
Nerves 3-12, they are part of the PNS
Conus medulliaris
caudal end of spinal cord, levels L1-L2
Cauda equina
collection of nerve roots that course inferiorly to reach corresponding intervertebral foramen. Inferior to conus medulliaris
Filum Terminale
extension of pia mater, anchors spinal cord caudally to coccyx
Major subdivisions of spinal cord white matter
Dorsal Funiculis, Lateral Funiculis, Ventral funiculus
Propriospinal fibers
Fibers confined to spinal cord, mostly located at margins of grey matter. They allow communication between neurons at the sae and distant spinal cord levels and are thought to be important in reflex circuitry
Gray matter regions
Dorsal horn, Ventral horn, and intermediate zone. Further divided into rexed lamina. Demarcations of lamina are based on size and shape of neurons, their inputs and projections
Does amount of white matter increase or decrease as you go rostral to caudal?
it decreases
