Spinal Cord Anatomy Flashcards
Gross appearance of the spinal cord
- begins superiorly from the_____
- termnares inferiorly in adults at the level of___; young child at the level of____
- occupies____ of the vertebral canal
- gives off____ plexus in the cervical region
- inferiorly tapers off into the____
foramen magnum
L1
upper border of L3
upper 2/3
brachial
cornus medullaris
Gross appearance of the spinal cord
- from the cornus medullaris , a prolongation of_____, called the____ descends into the____
- the spinal cord possess a____ longitudinal fissure called the_____ in the midline anteriorly
- also has a____ posterior furrow called the_____
pia matter; filum terminale; coccyx
deep ;anterior median fissure
shallow; posterior median sulcus
List the Spinal cord Enlargements
____enlargement
_____enlargement
cervical
Lumbar
Spinal cord Enlargements
cervical enlargement
-extends from___ to___
Lumbar enlargement
- from__ to ___
- below this enlargement, the cord tapers off to the____
C3; T2
L1-S3
conus medullaris
Which spinal cord enlargement is more pronounced and larger ??
Cervical enlargement is larger and more pronounced than the lumbar enlargement
GRAY MATTER OF THE SPINAL CORD
- seen as a__-shaped pillar with ___ and ___columns/horns
- a small___ column segment is present in the___ and _____ segments
- the gray matter comprises of a mixture of____ and___
- the nerve cells are ____polar
H
anterior and posterior
lateral; thoracic and upper lumbar
nerve cells; their processes
multi
the amount of gray matter present at any given level of the spinal cord is related to the amount of muscles innervated at that level
T/F
T
Gray and white matter have neuroglia and blood vessels
T/F
T
Nerve cell groups in the anterior gray columns
- the axons of larger nerves pass out the anterior gray column as____ efferents that innervates___
- the axons of smaller nerves pass out the anterior gray column as___ efferents that innervate the_____
alpha; skeletal muscles
gamma; intrafusal fibers of neuromuscular spindles
the nerves cells of the anterior gray columns are divided into 3 groups or columns:_____ ,____,and _____
medial, central, and lateral
Medial group of AGC
- present in___ segments of the spinal cord
- innervate the skeletal muscles of the___ and ____ including the____ and ____
most
neck and trunk
intercoastal and abdominal musculature
Central group of AGC
- present in ____ and ____segments
- C_to C_ innervates the diaphragm through the___ nerve
- also innervates the___ and ____ muscle
some cervical and lumbosacral
C3-C5; phrenic
trapezius and SCM
Lateral group of AGC
- present in____ and ____ segments
- responsible for innervating_____
cervical and Lumbosacral
skeletal muscles of the limbs
smallest group of AGC is ______
Central group
Nerve cell groups in the posterior gray columns
- there are 4 nerve cells groups
- 2 of the nerve cell groups extend____ of the spinal cord
- other 2 groups are_____ segments
- there may be a fifth group known as____ nucleus
the entire length
restricted to thoracic and lumbar
posteromarginal
Substantial gelatinosa group
- found at___ of PGC
- found_____ of spinal cord
- receive afferent fibers concerned with___,____,____ from the posterior root
apex
throughout length
pain ,temperature and touch
Nucleus proprius group
- situated____ to the substantia gelatinosa
- occupy ____of the spinal cord
- receives fibers of the ____column that is concerned with____,___, and ____
anterior
entire length
posterior white white
proprioception, 2-point discrimination and vibration
Nucleus proprius
Large or small
Large
Nucleus dorsalis group
- aka_____
- situated at the____ of the PGC
- extends ____ segment
- most of its cells are associated with____ endings( neuromuscular spindles and tendon spindles)
Clarke’s column
base
C8 to 3rd of 4th lumbar
proprioceptive
Visceral afferent nucleus group
- situated____ to nucleus dorsalis
- extends from____
- receives___ afferent fibers
lateral
L1-L3
visceral
Nerve cell groups in the Lateral gray columns
- extends from ___ to ___segment of spinal cord and give rise to_____ fibers
- a smaller group of cells are found in the ____segments of the spinal cord and they give rise to____ fibers
T1-L2 or L3
ganglionic sympathetic
S2-S4
parasympathetic
Nerve cell groups in the intermediate gray columns
- this part contains the _____ and ____nucleus
- sacral autonomic nucleus is located in the same place as______ but in the _____segments of spinal cord
intermediolateral nucleus and intermediomedial
intermediolateral nucleus
S2-S4
REXED LAMINAE
-gray matter is divisible into____ lamina marked by Roman numerals
10
REXED LAMINAE
lamina 1 is at____ of the___ horn
- lamina 2 corresponds to_____
- lamina 3-6 corresponds to____
the tip; post
substantia gelatinosa
nucleus proprius
REXED LAMINAE
lamina 7 corresponds to____ horn in ____segments
- lamina 8 corresponds to____ in___ segment but ______in___and____ segments
- lamina 9 corresponds to____ in___ horn
lateral
T1-L2
most of the anterior horn; thoracic
only the medial part ; cervical and lumbar
group of motor neuron; ventral
Lamina 8 also contains the Clarke’s nucleus in C8-L3 segments
T/F
F
It’s lamina 7
REXED LAMINAE
lamina X is the______. Includes the _______surrounding the central canal
gray substance that surrounds the central canal
substantia gelatinosa centralis
TRACTS OF THE SPINAL CORD
contains only large diameter axons which are myelinated
T/F
F
contains both small and large diameter axons which may or may not be myelinated
TRACTS OF THE SPINAL CORD
the fibers run in different directions:____,____,____
- some fibers are intrasegmental, i.e_____; and some are intersegmental
- fibers are grouped into tracts depending on their____
ascending , descending, horizontal
arise and terminate within a segment
functional modality
Gray commissure
- in transverse section of spinal cord, anterior and posterior gray horns are connected by a______’__shaped’
- at the center of the commissure is situated a___
transverse gray commissure; H
central canal
the central canal divides the gray commissure into___ and ____ gray commissure depending on which side it belongs to
anterior and posterior
central canal
central canal runs through only the thoracic and lumbosacral segments of the spinal cord
T/F
F
central canal runs throughout the length of the spinal cord
central canal
superiorly it corresponds with the____ of ____ and opens into the___ of the ____
- continues inferiorly with the ____where it expands into the____ and terminated below within the____ of _____
- it’s filled with___ and line by ____epithelium, the____ cells
central canal of the medulla oblongata
cavity of the 4th ventricle
conus medullaris
fusiform terminal ventricle
root of filum terminale
CSF; ciliated columnar ; ependyma
WHITE MATTER
- consists of a mixture of___,___,and ____
- its white color is due to the______
- divided into___,____,and____
nerve fibers, neuroglia, and blood vessels
high proportion of myelinated nerve fibers
anterior lateral and posterior
WHITE MATTER
Anterior: between____ and ____
-lateral: between_____ and ___
-posterior :between_____ and ——
midline and point of emergence of anterior nerve roots
anterior and posterior nerve roots
midline and point of emergence of posterior nerve roots
ARRANGEMENT OF NERVE FIBER TRACTS IN WHITE MATTER
-A tract(___/——) is a collection of____ with the same origin, course and termination
-within the CNS, a tract connects______of ___
-divided into 3
_____
______
_____
lemnisci/fasciculi
nerve fibers
2 masses of gray matter
ascending tracts
- descending tracts
- intersegmental and intrasegmental tracts
ASCENDING TRACTS OF THE SPINAL CORD
- go from_____ to _____
- the information carried are divided into 2
- Exteroceptive information: originates from____ eg_____
- Proprioceptive information: originates from______ eg _____
spinal cord to higher regions
outside the body. Eg pain temp touch
inside the body. Eg muscles and joints
Anatomical organization of ascending tract
- First order neurons
- cell bodies are in_____
- ____process connects with a sensory receptor ending while the____ process passes the posterior root to synapse on the second order neuron
dorsal root ganglion of spinal nerve
peripheral; central
Anatomical organization of ascending tract
Second order neuron
-give rise to axons that____ and ____ to higher level CNS and synapse with third order neuron
decussate and ascend
Anatomical organization of ascending tract
Third order neuron
- usually in the____
- gives rise to____ fibers that pass to a sensory region of the cerebral cortex
thalamus
projection
The ascending pathways only use 3 neurons. Never more, nerve less
T/F
F
though most of the neurons of the ascending pathway use the 3 order of neurons, some others engage with fewer or more
many of the neurons in the ascending pathways branch and give a major input to the____ which in turn activates the ____thereby maintaining_____
reticular formation
cerebral cortex
wakefulness
other ascending pathway branches pass to motor neurons and participate in ____activity
reflex muscular
A list of Ascending tracts
Mention like 9 or 10
Spinothalamic tracts:anterior and lateral
- DCML
- posterior spinocerebellar tracts
- cuneocerebellar tract
- anterior cerebellar tract
- spinotectal
- spinoreticular
- spinolivary tracts
- visceral sensory tracts
LATERAL SPINOTHALAMIC TRACTS
- pathway for___ and ____
- first order neuron at____
- the axons continue into the spinal cord and travel a distance of one or 2 segments of the spinal cord forming the____ of ____
- axons of first order neuron terminate by synapsing in the_____ of _____
- ____is the NT released at this point
pain and temperature
dorsal root ganglia
posterolateral tract of lissaeur
substantia gelatinosa of the posterior gray column
substance P
LATERAL SPINOTHALAMIC TRACTS
the axons of the second order neuron____ through the_____ and ____ of the same spinal segment and ascend in the _____of the spinal cord as the lateral Spinothalamic tract
-As this tract ascends, it is accompanied by the ____ and ______ and together forms the_____
-axons of the second order neurons ascend through the___and ____ to terminate in the 3rd order neuron in the____ of____
decussate
anterior gray and white commissures
contralateral white column
Anterior Spinothalamic tract and the spinotectal tract ; spinal lemniscus
pons and midbrain; ventral posterolateral nucleus of the thalamus
LATERAL SPINOTHALAMIC TRACTS
from the VPN, the third order neuron ascends through the ____ and _____to the____ area of the ____gyrus
internal capsule and corona radiata
somesthetic
post central
ANTERIOR SPINOTHALAMIC TRACT
- pathway for____ and ____
- first order neuron at ____and proceed to dorsal grey column
- axons of first order neuron terminate by synapsing in the_____ of _____
light/crude touch and pressure
dorsal root ganglia
substantia gelatinosa of the posterior gray column
ANTERIOR SPINOTHALAMIC TRACT
the axons of the second order neuron____ to the anterior gray and white commissures of the same spinal segment and ascend in the anterolateral white column of the spinal cord as the anterior Spinothalamic tract to the____
- then later joins___ lemniscus that ascends to___ of ____
- from the VPN, to the somesthetic area of the post central gyrus
decussate; medullar oblongata
spinal
VPN of thalamus
DCML
- pathway for____,___,and____
- fibers of first order neuron from the____ enter the spinal cord and pass to the_____ of the___ side
- they divide into____ and ____ branches
discriminative touch, vibratory sense and conscious muscle joint sense
dorsal root ganglion
posterior white column; same
long ascending and short descending
The short descending fibers of the DCML pathway are involved with_____
intersegmental reflexes
-the long ascending fibers off DCML pathways may also end by synapsing with cells in the___ grey horn with____ neurons and with___ cells
dorsal
internuncial
anterior
DCML
- many of the long ascending fibers travel upwards in the posterior white column as____ and ____
- FG is present throughout the length of spinal cord and contains long ascending fibers from the ___,_____,____, and ____spinal nerves
- FC is situated in the_____ and _____ of the spinal cord
- the fibers of FG and FC ascend ___laterally and terminate by synapsing on the second order neurons in the_____ and ____ of the _____
fasciculus gracilis(FG) and fasciculus cuneatus(FC)
coccygeal, sacral, lumbar, and lower 6 thoracic
upper thoracic and cervical segments
ipsi
nucleus gracilis(NG) and nucleus cuneatus(NC) of the medulla oblongata
Who is more medial to who
FG or FC
FG
DCML
the axons of the second order neurons (____fibers) sweep anteromedially around the____ and cross the median plane and decussate with corresponding fibers of opposite side
- the fibers ascend as a single compact bundle called the____ lemniscus to the___ (3rd neuron) of____
- from the VPN to the somesthetic area of the post central gyrus
internal arcuate
central gray matter
medial
VPN;thalamus
Posterior spinocerebellar tract
- pathway for information from the_____
- axons of first order neurons from ___enter the spinal cord and terminate at the second order neurons in the_____ aka ____
- the axons of the second order neurons ascend upwards through the_____ part of the _____ column of the___ side up to the____ then it joins the_____ and terminates at the_____
Unconscious muscle spindles ,tendons organs and joint receptors of the trunk and lower limbs
spinal root ganglion
nucleus dorsalis (Clarke’s column)
posterolateral part of the lateral white
same; medulla oblongata; inferior cerebellar peduncle; cerebellar cortex
Posterior spinocerebellar tract
doesn’t get to the thalamus or cerebral cortex
T/F
T
Posterior spinocerebellar tract
because the nucleus dorsalis only extends from____ to ___,axons entering the spinal cord in the ___ or ____segments ascends in the ____column until it reaches the L3 or L4 segment and enter the Nucleus dorsalis
C8-L3 or L4
lower lumbar or sacral
posterior white
Anterior spinocerebellar tract
-majority of the axons of the Second order neurons cross to the opposite side and ascend in the contralateral white column
T/F
T
Spinotectal Tract
- the axons of the first order neurons synapse in the____
- the second order neurons arise from there and___ the medial plane and ascend in the_____ column to the_____ of _____
- this pathway provides the afferent information for____ reflexes and bring about movement of the___ and ____ toward the source of the stimuli
posterior gray column
cross
anterolateral white
superior colliculus of the mid brain
spinovisual
eyes and head
Spinoreticular Tract
- the axons of the first order neurons synapse in the____
- the second order neurons arise from there and ascend the spinal cord in the ____column mixed with the____ tract
posterior gray column
lateral white
lateral Spinothalamic
most of the fibers of the spinoreticular formation are crossed or uncrossed ???
and terminate by synapsing with neurons of_____ in the _____
Uncrossed
reticular formation in the medulla oblongata
Summary of Functions of Ascending tracts
- lateral Spinothalamic tract:___ and ___sensations
- anterior Spinothalamic tract:____,___,___
- DCML:____,____,____
- ________reach the cerebellum by way of the anterior and posterior spinocerebellar tracts and the cuneocerebellar tract
- ___,___and___information is passed to the superior colliculus of the midbrian through the spinotectal tract for the purpose of spinovisual reflexes
pain and thermal
crude touch and pressure
2 point discrimination;vibration, and proprioception
unconscious information from the muscles, joints, skin and subcutaneous tissue
pain, thermal, and tactile
Summary of Functions of Ascending tracts
Spinoreticular tract:sensations from__,___,___ to the reticular formation
-Spinoolivary tract: An____ pathway for afferent to reach the_____
muscles, joints, and skin
indirect; cerebellum
CORTICOSPINAL TRACT
- this tract is concerned with ___,___,____movement . Especially those of___ parts of the limb
- the tract arises as axons of____ cells situated in the___ layer of the cerebral cortex
- most of the fibers from____
- 1/3 of the fibers arise from the_____
- 1/3 of the fibers also come from the____
- meaning most comes from____ gyrus and the rest is from___ gyrus
voluntary, discrete, skilled distal pyramidal 5th area 4 secondary motor cortex(area 6) parietal lobe (areas 3,1,2)
precentral; post central
CORTICOSPINAL TRACT
- stimulation of different parts of the precentral gyrus produces movements of different parts of the____ side of the body
- from their origin, the fibers cross the___,___ limb of_____,____ of midbrain ,____ of pons and then the____ of medulla
opposite
corona radiata; posterior limb of internal capsule; crux cerebi of midbrain; central part; pyramids
CORTICOSPINAL TRACT
- about___% of fibers cross to the other side
- the crossed fibers of the medulla enter the____ of the spinal cord and descend as the _____tract
- the Corticospinal fibers that do not cross in the pyramids decussations enter the ___of the spinal cord to form the ____tract;on reaching the appropriate level of spinal cord, the fibers____ through the _____ to reach the___ matter on the___ side of the cord and continue in the same manners as lateral corticospinal tract
80; lateral funiculus; lateral Corticospinal
anterior funiculus ; anterior Corticospinal
cross the midline through the anterior white commissure; gray; opposite
CORTICOSPINAL TRACT
the corticospinal tract fibers terminate in the grey matter at various level of the spinal cord (lamina___ to___)
-the___ neurons covey this impulse to the__ horn cells
4
7
internuncial
ventral
The neurons that give rise to the corticospinal tracts are called___ motor neurons
the ventral horn cells and their processes are called___ motor neurons
upper
lower
SPINAL CORD INJURIES
- people at risk are___ between age____and____ and those in a____ occupation or lifestyle
- spinal cord injuries in older patients is increasingly due to MVAs
young men
15 and 30
risk-taking
SPINAL SHOCK
-this is the loss of sensation followed by _____with initial loss but gradual recovery of___ following a spinal cord injury (usually a____ )
motor paralysis
reflexes
complete transection
reflexes below the level of injury are_____ (___reflexia) or___ (___reflexia) while those above the level of injury_____
depressed
Hypo
absent; a
remain unaffected
CLASSIFICATION OF SCIs
- Mechanism of injury
- flexion(bending__)
- hyperextension(bending___)
- rotation(either ___or____rotation)
- compression (_______)
forward
backwards
flexion or extension
downward motion
LESIONS OF SPINAL CORD
- In a complete transection at or above C4 level, the patient__ due to____
- if below C5, the result is_____(paralysis of____)
- transection at thoracic level leads to____ (paralysis of____)
dies; paralysis of diaphragm
quadriplegia; both arms and legs
paraplegia; lower half of the body
One commonality is both paraplegia and quadriplegia is?????
control of bladder is lost
Types of Paralysis
(1)Hemiplegia:paralysis of______
(2)Monoplegia: paralysis of____
(3) Diplegia: paralysis of______
(4) paraplegia
(5) quadriplegia
one side of the body and includes the upper limb, one side of the trunk, and lower limb
one limb only
2 corresponding limbs (upper and lower limb)
Lesions of pyramidal tracts
(1)Babinski sign:__ toe become _____while the__ toes___ in response to_____. The normal response should be_____
big ;dorsally flexed
other; fan out
scratching the skin alon the lateral aspect of the sole of the foot
plantar flexion of all the toes
babinski sign is present in___ year of life because_____
first
the corticospinal tracts aren’t myelinated yet till the end of first year of life
Lesions of pyramidal tracts
absence of superficial abdominal reflex :there should be___ of abdominal muscles when____
Abscence of cremasteric reflex: the cremasteric muscle should___ when_____
Loss of performance of fine-skilled voluntary movements
contraction
the abdominal skin is stroked
contact; the skin of the inner medial thigh is stroked
LESIONS OF EXTRAPYRAMIDAL TRACTS
-severe paralysis with ___muscular atrophy except due to disuse
-clasp-knife reaction: when passive movement of a joint is attempted there is___ due to____ of the muscles.The muscles, on stretching ,give way to______
little or no
resistance; spasticity
neurotendinous organ-mediated inhibition
LOWER MOTOR NEURON LESION \_\_\_\_\_ paralysis _Atrophy _Loss of reflexes _Muscular\_\_\_\_ :\_\_\_\_ of muscles _Muscular\_\_\_\_:\_\_\_\_\_\_\_muscle
flaccid
fasciculation; twitching
contracture; shortening of the paralyzed
ANTERIOR CORD SYNDROME
- ____of the anterior spinal cord, usually a___ injury
- sudden complete motor paralysis at lesion and below
- __creased sensation(including___) and loss of____ sensation below site
- ____ and _____remain intact
compression
flexion
decreased; pain
temperature
touch , position vibration and motion
Central cord syndrome may be caused by___
ventral cord syndrome can be caused by ____
syringomyelia
poliomyelitis
Brown - sequard Syndrome
- damage to______
- caused by___ trauma or_____,____ or destruction of a blood vessel , or infectious or inflammatory diseases like___or ____, a spinal cord tumor,trauma(like a puncture wound to the neck or back)
one-half of the cord on either side
penetrating
ruptured disc
ischemia
tuberculosis, MS
the SCI symptoms that would occur in brown-sequard syndrome is
- _____on___ side of the body
- _____ on the_____ side
weakness or paralysis(hemiparalegia)
one
loss of sensation (hemianaesthesia); opposite
_____ arteries supply the internal capsule
Lenticulostriate
Lesion of motor pathway below the pyramidal decussation would affect the ____lateral side
Contralateral
Lesion at corona radiata or internal capsule could lead to patient presenting with APHASIA which is the \_______
T/F
T
Inability to understand language (spoken or written)
Symptoms of someone with a cerebrovascular accident is
FAST
What do they stand for
F-facial assymetry
A- arms are no longer moving
S-slurred speech
T-act on time
Difference between fasciculation and fibrillation of a muscle
Fasciculus-whole muscle
Fibrillation-individual muscle
Both involves twitching
Fibrillations can be visible seen
T/F
F
Fibrillations are too small to be seen as a visible muscle contraction
Upper motor neuron disorders produce a___ weakness of movement (____), which differs from the complete loss of muscle activity caused by paralysis (___).
graded
paresis
plegia
Fasciculation and fibrillations also occur in upper motor lesions
T/F
F
Epidural space – space between the____ and the______ filled with____ and a network of___
vertebrae
dura mater
fat; veins
Denticulate ligaments – delicate shelves of______ that attach the_____ to _____
pia mater
spinal cord to the vertebrae
Cauda equina – collection of_____ at the____ end of the____
nerve roots
inferior
vertebral canal
Dorsal and ventral roots fuse laterally to form______
spinal nerves
Most white matter pathways exhibit somatotopy
T/F
T
The spinocerebellar tracts contribute to sensory perception
T/F
F
They do not
lateral spinothalamic tract
Specific or non-specific pathway
Non specific
DCML pathway
Specific or non-specific pathway
Specific
In Spastic paralysis, There is no voluntary or involuntary control of muscles
T/F
F
In Flaccid paralysis There is no voluntary or involuntary control of muscles
T/F
T
Cross sectioning of the spinal cord at any level results in total motor and sensory loss in regions_____ to the cut
inferior
Paraplegia – transection between___ and ___
Quadriplegia – transection in the____ region
T1 and L1
cervical
In poliomyelitis
There is Destruction of the_____ neurons by the poliovirus
anterior horn motor
Lou Gehrig’s disease – neuromuscular condition involving destruction of _____neurons and fibers of the______ tract
anterior horn motor
pyramidal
Amyotrophic Lateral Sclerosis (ALS)
- Death occurs within____ years
- Linked to malfunctioning genes for____ and/or superoxide dismutase
five
glutamate transporter
Amyotrophic Lateral Sclerosis (ALS) Symptoms include loss of the ability to speak, swallow but the person can breathe
T/F
F
Can’t breathe too
CNS is established during the___ month of development
first
Gender-specific areas appear in response to_____ (or lack thereof)
testosterone
Maternal exposure to radiation, drugs (e.g., alcohol and opiates), or infection can harm the mother but not the fetus
T/F
F
Harms both
Smoking decreases___ in the blood, which can lead to____ and fetal brain damage
oxygen
neuron death
The____ of the diencephalon is one of the last areas of the CNS to develop
hypothalamus
Visual cortex develops( slowly or rapidly?) over the first____
Slowly
11 weeks
Age brings some cognitive declines, but these are not significant in healthy individuals until they reach their____
80s
Excessive use of alcohol causes signs of_____ unrelated to the aging process
senility
Secondary fibers of lateral spinothalamic tract are joined in brainstem by fibers of the_____ tract
trigeminothalamic
Tertiary fibers of the lateral spinothalamic tract are also called_____ fibers and synapse in postcentral gyrus:
corticopetal
Tertiary fibers of the lateral spinothalamic tract form part of internal capsule.
T/F
T
Medial Lemniscus System
Also called ____system.
posterior column
fasciculus cuneatus Also conveys proprioceptive sensation from legs to cerebellum.
T/F
F
Arms
Posterior Spinocerebellar Tract
Originates in ____ and _____ region
Anterior Spinocerebellar Tract
Originates in_____ and _____
thoracic and upper lumbar
lower trunk and lower limbs
Posterior Spinocerebellar Tract Consists of (crossed or uncrossed?) fibers that enter cerebellum through\_\_\_\_ cerebellar peduncles.
Anterior Spinocerebellar Tract Consists of (crossed or uncrossed?) fibers that\_\_\_ in\_\_\_ and enter cerebellum through\_\_\_\_ cerebellar peduncles.
Uncrossed; inferior
Crossed; recross; pons; superior
Both anterior and Posterior spinocerebellar tract Transmits ipsilateral proprioceptive information to cerebellum.
T/F
T
Muscle spindles are contractile where?
At the ends of in the center
At the ends
Gamma neurons are modulated by _____ fibers in the spinal cord
Ascending or descending
Descending
Golgi tendon organs
Encapsulated or non encapsulated
Encapsulated
there are weak and strong action potentials
T/F
F
Changing a sensory stimulus into an action potential is called____
transduction
Lesion at anterior whit column of SC, which descending tracts would be affected
Tectospinal Rubrospinal Olivospinal Vestibulospoinal Cerebrospinal
T F T T F
INNERVATION of the cornea is by why nerve?
Opthalamic nerve
In myeloschisis, spinal cord is open as neural tube fails to form
T/F
T
Cystic swellings occur most in ___ and ____ regions of spinal cord
Thoracic and lumbar
During development of spinal cord:
- all neurone and glialcells are derived from ventricular zone or ependymal layer
- the marginal zone is located between the neuroepithelial and mantle zones
- the mantle layers give rise to the white matte rod spinal cord
- sulcus limitans is a vertical groove that’s seperating roof plate from floor plate
- enlargement of alar plate is responsible for producing the anterior median fissure
T F F T F
Neuroectoderm differentiates between day 22-23 of embryonic life
T/F
T
Anterior Neuropore closes on day ___
Posterior Neuropore closes on day ___
26
28
Medial longitudinal fasciculus ends in cervical spinal cord
T/F
T
The extra pyramidal system have uncrossed tracts
T/F
If T, list them
T
Vestibulospinal
Reticulospinal
Glial cells found primarily in the marginal zone of spinal cord is ____
Oligodendrocytes
Inferior petrosal sinus connects cavernous sinus to ____
Internal jugular vein
____ artery is likely to be cut in a tracheostomy from the front
Thyroidae ima artery
Middle meningeal artery pass through the foramen spinosum
T/F
T
Only cranial nerve to emerge from the posterior part of brain stem is __?
Trochlear nerve
