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spinal cord
Part of the central nervous system (CNS) and continuous with the brainstem(medulla). Major reflex center & conduction pathway between the body & brain. Housed within the vertebral column, it extends from the foramen magnum to the L1-L2 vertebral level in adults (usually). TERM 2
spinal cord enlargements
DEFINITION 2 cervical & lumbosacral areas TERM 3
cervical enlargement
DEFINITION 3 C4-T1 spinal cord levels; associated with brachial plexus (innervation of upper limb) TERM 4
lumbosacral enlargement
DEFINITION 4 L1-S3 spinal cord levels; associatedwith lumbar & sacral plexuses (innervation of lower limb) TERM 5
conus medullaris
DEFINITION 5 tapering inferior end of the spinal cord thatterminates inferior to the lumbar enlargement
filum terminale internum
continuation of pia mater; extends asslender, anchoring filament from the tip of the conus medullaris TERM 7
number of pairs of spinal nerves
DEFINITION 7 31 TERM 8
number of cervical pairs of spinal nerves
DEFINITION 8 8 TERM 9
number of thoracic spinal nerve pairs
DEFINITION 9 12 TERM 10
number of lumbar spinal nerve pairs
DEFINITION 10 5
anterior roots
Contain motor (efferent) fibers and presynaptic autonomic fibers;Cell bodies of axons contributing to anterior roots are located within the anterior horn ofgray matter within the spinal cord. TERM 17
posterior roots
DEFINITION 17 Contain sensory (afferent) fibers;Cell bodies of axons contributing to posterior roots are located in the spinal ganglia(dorsal root ganglia) that appears as a small swelling TERM 18
spinal nerve
DEFINITION 18 where Anterior & posterior roots unite; mixed (carries sensory & motor innervation) ; housed within the intervertebral (IV) foramen TERM 19
posterior
ramus
DEFINITION 19 one of the two spindles that spinal nerves separate into; (supplies skin & deep muscles of the back) TERM 20
anterior
ramus
DEFINITION 20 one of the two spindles that spinal nerves separate into; (supplies limbs and rest of the trunk)
why are the more inferior lumbar spinal
nerves the most vulnerable?
The lumbar spinal nerves increase in size from superior to inferior, while the lumbar IV foramina decrease in diameter; thus, the more inferior nerves are more vulnerable to compression. (L5 spinal nerves are largest, while their IV foramina are smallest.) TERM 22
How spinal nerves exit the spinal canal
DEFINITION 22 C1-C7 spinal nerves exit superior to the vertebrae; C8-rest exit below the vertebrae TERM 23
point at which the spinal cord
ends
DEFINITION 23 ~L TERM 24
cauda equina
DEFINITION 24 the nerve roots that continue past the termination of the spinal cord TERM 25
disc herniation
DEFINITION 25 protrusion of the nucleus pulpous into the spinal canal. May directly compress nerve roots or the spinal cord, resulting in pain &/or neurologic deficits. *** affects the nerve root immediately inferior to it
what does the spinal dura mater form?
spinal dural sac TERM 32
spinal dural sac
DEFINITION 32 a long tubular sheath within vertebral canal; Extends inferiorly to the S2 vertebral level;Pierced by spinal nerves;Anchored to coccyx by the filum terminale externum;Continuous with cranial dura mater at foramen magnum. TERM 33
epidural space
DEFINITION 33 actual space superficial to dura mater. Occupied by fat & the internal vertebral venous plexus. TERM 34
subdural space
DEFINITION 34 potential space between the dura & arachnoid mater TERM 35
epidural
block
DEFINITION 35 during this,anesthetic can be injected into the epidural space, which would directly affect the spinal nerve roots of the cauda equina after they exit from the dural sac. The patient would lose sensation inferior to the level of the block.This is frequently used during labor & delivery.
spinal arachnoid mater
Delicate, avascular membrane (middle layer); not attached to dura mater, but held against it by pressure from the CSF TERM 37
what does the spinal arachnoid mater enclose
& contain
DEFINITION 37 subarachnoid space containing cerebral spinal fluid (CSF) and vasculature tothe spinal cord. TERM 38
lumbar spinal puncture
DEFINITION 38 performed to obtain a CSF sample from the lumbar cisternthat houses the cauda equina. A needle is inserted into the subarachnoid space while the patient is lying on his/her side with the trunk flexed. It is usually performed at the L3/L or L4/L5 vertebral level. TERM 39
lumbar cistern
DEFINITION 39 an enlargement of the subarachnoid space between the termination of the spinal cord (L2 level) & termination of the dural sac (S2 level) TERM 40
spinal pia mater
DEFINITION 40 Innermost covering membrane directly covering the spinal cord, nerve roots, & vessels.
Anterior & posterior segmental medullary
arteries
(from spinal branches of arteries) enter the vertebral canal through the IV foramina to join with spinal arteries. They are chiefly located around the cervical & lumbosacral enlargements, where the need for a good blood supply is greatest. TERM 47
radicular arteries
DEFINITION 47 (anterior & posterior) run along the nerve roots to supply the spinal nerves and their coverings. TERM 48
internal vertebral venous plexus
DEFINITION 48 what the veins draining the spinal cord in the epidural space TERM 49
external vertebral venous plexus
DEFINITION 49 what the veins communicate with on the external surface of the vertebrae TERM 50
spinal cord injury
DEFINITION 50 direct damage to the cord itself or indirectly from damage to surrounding tissues.extensive PT, OT, & other rehab interventions are often required after it has healed to assist the person in coping with the resulting disability.
complete cord injury
neural messages cannot be relayed below the level of the injury, resulting in paralysis TERM 52
incomplete spinal cord injury
DEFINITION 52 some movement & sensation below injury
