The Spinal Cord
lamina ___ is at the neck of the dorsal horn and neurons receive ____ fibers from the corticospinal and rubrospinal and gives rise to some axons of the ___ tract
V; descending; spinothalamic
lamina ___ is present on in the cervical and lumbar segment that receives _____ and ____. neurons are involved in the integration of ____ neuron processes. *these axons are usually headed to the ____.
VI; muscle spindle; joint afferents; somatic; cerebellum
lamina ____ contains the nucleus dorsalis of Clark which extends from C8-L3. axons form the dorsal _______ tract which relays information to the ipsilateral ___.
VII; spinocerebellar; cerebellum
lamina __ - __ is located in the ventral horn of the gray matter. neurons receive inputs form ____ motor tracts from the cerebral cortex and brainstem. they are somatotopically arranged. the gray matter around the central canal forms lamina ___. * where the _____ fibers synapse
VIII-IX; descending; X; corticospinal
occlusion of the _____ artery leads to acute thoracic cord syndrome with paraplegia
anterior spinal
2 smaller branches arise and join to form the _____ at the area where the 2 vertebral arteries form a confluence
anterior spinal artery
_____ tract transmits the sensation of nondiscrimitive touch (crude touch) to the primary sensory cortex
anterior spinothalamic
________ consisting of _______ is ventral to the gray commissure
anterior white commissure; decussated axons
_______ tracts may carry all somatosensory modalities (pain, temperature and crude touch) but routes may be different
anterolateral system of ascending tracts
corticospinal tracts is a long descending tract that arises in the _____, passes through the medullary _____ and terminates in the ______
cerebral cortex; pyramids; spinal cord
in the corticospinal tract cells associated with the arm are represented on the ____ convexity, and those of the legs are on the _____ convexity. many of the axons control _____ of the distal parts of the extremities
lateral; medial; fine movements
_____ tracts mediate motor functions including voluntary and involuntary movement, regulation of muscle tone, modulation of spinal segmental reflexes, and regulation of visceral functions
long descending tracts
lower motor neuron paralysis (LMN) result in:
loss of muscle tone; atrophy of muscle; loss of all reflex and voluntary movement; hemiplegia (both limbs on one side), monoplegia (one limb), diplegia (both arms) paraplegia (both legs), quadriplegia (all limbs)
_____tract conveys information about pain and temperature
lateral spinothalamic
______ tracts receive inhibitory inputs from the cerebellum and excitatory input s from the vestibular apparatus. impulses transmitted facilitate ipsilateral extensor _____ neurons and increase ____ tone. control the muscles that maintain _____ and ______. (pons and medulla)
lateral vestibular; motor; muscle; upright posture; balance
Spinoreticular tract is similar to ___ tract. responsible for ____ responses to ___, in case of injury. pain motivation, affective and behavioral responses
neospinothalamic; autonomic; pain
Paleospinothalmic tract is similar to ______ tract. neurons in deep dorsal horn and intermediate gray matter. axons ascend both ipsilateral and contra laterally in the ventral spinal cord. axons synapse on ______ and then project to intralaminar thalamic nuclei. thalamic nuclei project to _____. transmits ___ pain
neospinothalamic; reticular formation; cingulate gyrus; slow
SC transmit the signals to somatic and visceral target sites through the _____ roots
ventral
_____ funiculi is between the anterior median fissure and where the ventral roots exit
ventral (anterior)
there are ____ funiculi on each half of the spinal cord
3
____ pairs of nerves emerge from the ____ in the _____
31; spinal cord; intervertebral foramina
lamina ___ and ___ contain the proper sensory nucleus and receives input from the substantia gelatinosa and contribute to the ____ tracts mediating pain, temperature, and crude touch
3; 4; spinothalamic
the cervical enlargement includes ____ lower cervical and the ___ thoracic segments
4; 1st
the ____ cervical spinal nerve exits through the foramina just ___ to the ___ vertebra
8th; rostral; 1st
______ is a progressive degenerative disease of the corticospinal tract (upper motor neuron) and ventral horn cells (lower motor neuron). lower neurons degeneration in the cervical cord results in _____ and eventually loss of control in muscle of the _____, ___, and ______. involuntary twitching occurs and bladder and bowel function are impaired due to _____ autonomic pathways
ALS; weakness; hand; trunk; lower limbs; descending
lamina ______ cells receive primarily pain, temperature, and crude (non-discrimitive) touch
I-IV (in the dorsal horn)
lamina ____ contains terminal of dorsal root fibers mediating pain and temperature sensations on a group of neurons. axons cross to the _____ side and ____ as lateral _____ tract
I; opposite; ascend; spinothalamic
lamina ___ contains the substantia gelatinosa. neurons modulate ____ and ____ afferents. activation of pain receptors results in the release of _____ and ____
II; pain; temperature; substance P; glutamate
_______ consists mainly of ascending fibers but contain some descending fibers. ____ axons control the position of the head in response to excitation by the labyrinth of the vestibular apparatus
MLF; motor
in the Spinomesencephalic tract axons ascend to the _____. sensory information is believed to be transmitted to ____. involved in ____ inhibition through descending indirect projection to the spinal cord
PAG; amygdala; pain
in most instances (75%), the PSA arises from the ____, the minority of the time it arises from the _____ (25%)
PICA; vertebral artery
caudally the spinal dura ends at the _____ vertebra
S2
SC transmits information to higher centers through _____ tracts
ascending
at the lower border of the pons the two vertebral arteries join together to form the _____ or ____
basilar artery; vertebro-basilar artery
the nerve root forms the _____ plexus and innervates the upper extremities
brachial
_______ syndrome consists of hemisection of the spinal cord as seen in fracture dislocation of vertebrae, tumor. primary characteristics is the dissociation of function between ________ and ____ and _____ sensation.
brown-sequard; conscious proprioception; pain; temperature
______ is formed by lumbosacral nerve roots
cauda equina
_____ consists of a bundle of nerve roots of the spinal nerves caudal to the second lumbar vertebra
caudal equina
______ is located in the gray commissure
central canal
the _____ segments in the spinal cord are the largest. In each half of the spinal cord, the dorsal funiculus is divided into the ______ and ____
cervical; fasciculus gracilis; fasciculus cuneatus
the spinal cord is enlarge at the ___ and ___ regions
cervical; lumbar
In the ____ region the spinal nerves exit just ____ to the vertebra of the same name
cervical; rostral
At S2, a caudal thin extension of the spinal dura, ______ surrounds the filum terminale
coccygeal liagment
____ results in deficiency of enzymes necessary for vitamin B12 absorption. sensory loss (tingling and loss of sense of vibration and position). motor disturbance- upper motor neuron dysfunction which may include weakness of the lower limbs and an ataxic galt
combined systems disease
conical shaped end of the spinal cord
conus medullaris
the _____ is the conical shaped caudal end of the spinal cord. It is at the caudal edge of the 1st edge of the 2nd vertebra
conus medullaris
filum terminale internum extends from the ____ and passes through the caudal end of the ____ at S2
conus medullaris; dural sac
____ tract is involved in the control of voluntary fine movements. it is the largest and most important fiber tract. (cerebral cortex)
corticospinal
loss of conscious proprioception (clumsy) of the upper body will be due to _____ fibers
cuneate
_____ tract convey information about unconscious proprioception related to the upper limb
cuneocerebellar
the gray matter contains mainly
dendrites; neuronal cell bodies; myelinated and unmyelinated axons which are either projecting from the white matter to innervated neurons in the gray matter, or exiting the gray matter to the white matter
SC receives signals from higher centers through ____ tracts
descending tracts
the routes carry carrying somatosensory modalities are different. They are _____ route and _____ route
direct; indirect
_____ funiculus is between the dorsal horn and the dorsal median septum
dorsal (posterior)
_______ tract (nonconscious proprioception) are in the DRG and innervates muscle spindle. fibers project to the ______ whose axons ascend ipsilaterally to the ____ cerebellar peduncle in the medulla and terminate in the ____ of the cerebellum.
dorsal (posterior) spinocerebellar; nucleus dorsalis of Clarke; inferior; vermis
the _____ funiculus contains 2 ascending tracts (fasciculus gracile and cuneatus). *below T6 is ____, T6 and above is ___. gracile is in ____ direction. cuneate is in ____ direction
dorsal (posterior); gracile;cuneate; medial; lateral
Each spinal nerve consists of _____ and ____
dorsal root (afferent fibers); ventral roots (efferent fibers)
With lesion of the ______. sectioning of 3 consecutive dorsal root causes abolition of all ____ function. with muscle tone also dependent on segmental reflexes caused by the section of a dorsal root results in loss of ____ innervated by the affected segments
dorsal root; sensory; muscle tone
the different tracts in the spinal cord are referred to as ____, ____, and ____ funiculi
dorsal; ventral; lateral
_____ consist of crossed and uncrossed, ascending and descending fibers that arise and terminate in the spinal cord. mediate ____ mechanisms of the spinal cord, such as coordination of upper and lower limb movements
fasciculi Propii; reflex
in the caudal medulla, the PSA supplies
fasciculus gracilis and cuneatus and their nuclei; spinal trigeminal nucleus, dorsal and caudal portion of the inferior cerebellar peduncle; portions of the solitary tract ; dorsal motor nucleus of vagus nerve
______ extends to all levels of the spinal cord and contain fibers from the lower limbs. Mediates conscious proprioception that include kinesthetics and discriminative (fine) touch, and vibration. these axons from medulla cross to form the _____ and terminate on the ______. Axons of VPL terminate in the _____ cortex.
fasciculus gracilis; medial lemniscus; contralateral VPL neurons of the thalamus; sensorimotor
_____ contains ascending fibers from upper limbs
fasiculus cuneatus
____ has a thin film enclosed in ___ consisting of ___ and ____ which emerge from the conus medullaris
film terminale; pia; ependymal cells; astrocytes
the spinal arachnoid mater rostrally passes through the _____ to join the ____ arachnoid and ____ to surround the caudal equina
foramen magnum; cranial; caudally
_____ is a bundle containing one or more tracts or fasciculus
funiculus
loss of proprioception regarding kinesthetics is due to ___ fibers
gracile
the 2 sides of the spinal cord are connected by the _____
gray commissure
_____ pathways are involved in autonomic, endocrine, and arousal component of pain
indirect
preganglionic cells within lamina vII constitute the _____ cell column in the _____ and ____ neurons.
intermediolateral (IML); thorocolumbar cord; parasympathetic
_____ funiculi is between the sites where the dorsal roots enter and the ventral roots exit the spinal cord
lateral
______ funiculus contain long ascending and descending tracts ex* corticospinal
lateral
depending on the extent of the lesion there is upper motor neuron (UMN) paralysis from corticospinal tracts as seen by:
loss of muscle tone; spastic after a few weeks; hyperreflexia especially in the legs. superficial reflexes are either lost of diminshed
the ____ plexus innervates the lower extremities
lumbar
_____ innervates the bladder *also has CSF in it from the cistern
lumbar enlargement
the ____ segments appear circular in transverse sections. segments L_ and L_ are similar to those in the lower thoracic and contain IML. L_-L_ provide motor innervation to large muscles in the lower extremities
lumbar; 1 and 2; 3-5
the _____ and ____ plexus form the lumbar enlargement
lumbar; sacral
_____ tract adjust position of the head in the response to changes in _____ such as keeping the head stable while walking (pons and medulla)
medial vestibulospinal; posture
the anterior spinal artery supplies the ____ structure of the medulla including the _____, ______, ______, _____, and the ______
medial; pyramids; medial lemniscus; medial longitudinal fasciculus; hypoglossal nucleus; inferior olivary nucleus
90% of the fibers cross over in the ___ and ____ to form the lateral corticospinal tract which descends and synapse in the ventral and dorsal horn. the remaining uncrossed fibers form the ____ corticospinal tract which cross over later in the spinal cord. corticobulbar fibers leave the ___ and project to ____ nerves and other brainstem nuclei
medulla; spinal cord; anterior; medulla; cranial
spinal dura mater consists of only the _____ layer
meningeal
spinal epidural space is located between the ___ layer of the dural and the _____ of the vertebra
meningeal layer; periosteum
renshaw cells within lamina VII are interneurons which regulate ___ neurons through "recurrent inhibition"
motor
____ results in demyelination of tracts. impairment of mobility, paralysis, and disturbances in vision and bowel and bladder function
multiple sclerosis
the is a direct pathway that mediates, pain, temperature and simple tactile sensations. deficits on the cervical level would be complete loss of pain, temperature, and tactile sensation on the contralateral side of the body
neospinathalamic tract
axons of the ______ transit information about the status of the ____ thus enabling this region to coordinate and integrate neural signals controlling movement lower limb muscles and posture
nucleus dorsalis of Clarke; muscles
the spinothalamic modalities of ____ and ____ are preferentially lost, whereas the _____ function of the dorsal columns are relatively preserved
pain; temperature; proprioceptive
the three indirect pathways are:
paleospinothalamic; spinoreticular; and spinomesencephalic tract
spinal dura is single-layered and lacks the _____ of the cranial dura
periosteal layer
Thin filament enclosed in ___ and consisting of _____ , ____ , and ____ , emerges from the ____. This filament is called ________
pia; glial cells; ependymal cells; astrocytes; conus medullaris; filum terminale
other neurons within lamina VII include _____ and _____ cells.
preganglionic; renshaw
most of the pyramids passing through caudal end of medulla pass to the contralateral side to form the ______ decussation
pyramidal
_____ tract consists of 3 fiber systems that mediate motor, autonomic functions and modulate pain (pons and medulla)
reticulospinal
clusters of cells are arranged in 10 zones called ________
rexed laminae I-X (where the synaptic transmission occurs)
the spinal pia mater is a _____ membrane and projects into the ____ of the spinal cord
vasculated; ventral fissure
_____ tract is associated with axons from the red nucleus cross over in the midbrain and descend to the contralateral spinal cord. fibers are _____ arranged. facilitates ____ motor neurons and inhibits ____ motor neurons (midbrain)
rubrospinal; somatotopically; flexor; extensor
clinical phenomenon in which damage to the spinothalamic tract leaves the sacral region is called _____
sacra sparring
Spinal cord receives _______ information from _____ and _____ receptors through ______ roots
sensory; somatic; visceral; dorsal (always periphery)
the neospinothalamic tract is ______ organized- sacral and lumbar segments are dorsolateral to cervical and thoracic- so any expansion of the spinal cord will affect the ____ and ___ fibers first
somatotopically; thoracic; cervical
_____ is connected to the dura through connective tissue, trabeculae
spinal arachnoid mater
complete transection of ______ results in loss of muscle tone, motor reflex activity, visceral sensation and somatic sensation below the level of the transection
spinal cord
_____ space is an actual space in which the venous plexuses are located and is used clinically for the administration of epidural anesthesia- paravertebral nerve block
spinal epidural
The _______ is located within the ______ and contains neurons that give rise to _____ entering the spinal cord
spinal ganglia (DRG) (pseudo-unipolar) ; intervertebral foramen; afferent
In the dorsal horn of the spinal cord, the gray matter reaches the surface of the cord. this is not seen on the _____ surface
ventral
______ is based on the sites where spinal nerves emerge from the spinal cord
spinal segmentation
the vertebral arteries ascend through the ____ column and enter though the ____ foramen of the ____ cervical vertebrae and then later enters the ____ through the _____
spinal; transverse; 6th; cranium; foramen magnum
the vertebral arteries and the basilar arteries are _____ arteries and therefore not as subject to _____ due to the buildup of _____ as are internal carotids
straight; blockages; cholesterol
both of the vertebral arteries first arise from the _____ artery of the ____
subclavian; aorta
a large number of propiospinal fibers which connect different levels of the _____
substantia gelatinosa
_____ is associated with a cyst (syrinx) that forms within the spinal cord. expands and elongates over time, destroying the center of the spinal cord. damage may result in pain, weakness, and stiffness in the back, shoulders, arms or legs. other symptoms may include headaches and loss of the ability to feel extremes of hot or cold, especially in the hands and disruption to temperature. it may also affect sweating, sexual function and bladder and bowel control
syringomyelia
________ - loss of pain, temperature , and tactile sensation can also occur after damage to the area around the central canal.
syringomyelia
_____ is a late consequence of syphillis. aka as tertiary syphilis or neurosyphilis. neurons in the DRG _____ especially in the lower thoracic and lumbarsacral segments. degeneration of ____ with loss of vibratory sensation, two-part discrimination, and conscious proprioception (results in ataxia - loss of full control of bodily movements)
tabes dorsalis; degenerate; fasciculus gracilis
______ tract is associated with neurons are in the superior colliculus. axons terminate in the upper ______ segments. aid in directing ____ movements in response to visual and auditory stimuli (midbrain)
tectospinal; cervical; head
At the level of the medulla, each vertebral artery gives off ____ , ____ , and _____
the anterior spinal artery; posterior inferior cerebellar artery; posterior spinal artery
the sacral segments are small and contain small amount of white matter and abundant gray matter- WHY?
the neurons are there but all the axons either have not entered the spinal cord or they have not exited when talking about motor fibers
spinal cord is critical component of the CNS for
the transmission of sensory information to the brain as well as for the regulation of mortor and autonomic functions
the spinal pia mater is _____ compared to the cranial pia mater
thicker
____ segments are smaller because they contain smaller amounts of gray and white matter. the ____ as well as the _____ is located in this segment. the spinal nerves in the rostral thoracic segment innervate the ____ neurons in the ____ and ____ muscle and those in the _____ segment innervate the abdominal muscles
thoracic; IML; nucleus dorsalis of Clarke; motor; back; intercostal; caudal
the spinal cord and its blood supply are most vulnerable in the ____ segment and in the ____ portion of the cord
thoracic; anterior
In ____ , ____ , and ____ regions, spinal nerves exit though the foramina just ____ to the vertebra of the same name
thoracic; lumbar; sacral; caudal
_____ of the pia tissue (dentate ligaments) anchor the spinal cord to the arachnoid and the inner surface of the dura
toothed ligaments
______ tract are in in the DRG. axons terminate in the dorsal horn. * only tract that decussates in the spinal cord. convey information about ______ and postural adjustments to the cerebellum
ventral (anterior) spinocerebellar; whole limb movements
Lesion of ____. abolish motor functions of the muscles innervated by afferent segments
ventral root
____ and ____ roots are joined ____ to the DRG and form the common spinal nerve trunk which is connected with the sympathetic chains of paravertebral ganglia located on either side of the vertebral column through the white and gray rami
ventral; dorsal; distal
Spinal cord is located within the _____ canal and extends from the ____ to the rostral edge of the ___ lumbar vertebra
vertebral; foramen magnum; second
the gray matter in the spinal cord is surrounded by ____ matter of ____ and ____ myelinated and unmyelinated axon fibers (tracts of fasciculus)
white; ascending; descending
________ consists of the myelinated and unmyelinated dorsal root fibers that are on the medial portion of this zone
zone of lissauer or dorsolateral fasciculus