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