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Presentation
spinal cord
Spinal cord
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Origin:
foramen megnum continous with
medulla oblongata of brain
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Termination
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in adult
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at the lower boarder of L1
in child
at the upper boarder of L3
Menings
The spinal cord is surrounded by three membranes
1 dura mater
2 :arachnoid mater
3:pia mater
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Function’
Protection
Also by cerebrospinal fluid present in the subarachnoid space
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In the cervical region
it gives origin to the brachial plexus
lower thoracic region and lumber
region
it gives origin to lumbosacral plexus .
superiorly
the spinal cord is fusiformly enlarge the enlargement
is referred as the cervical and lumber enlargement
inferiorly
the spinal cord tapers off into the conus medullaris
from the apex of which a prolongation of pia mater
the filum terminale descend to be attached to the
posterior surface of the coccyx.
location
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The cord lie in midline
anterior median fissure
posterior median sulcus.
Along the entire length of the spinal cord are
attached 31 no of spinal nerves by the
anterior or motor roots and
Posterior root or sensory
posterior root ganglion
cells which gives rise to peripheral and center
nerve fibber
Structure of spinal cord
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gray mater
inner
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white mater
Outer
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GRAY MATER
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On croos section the gray mater is seen H-shaped pillar with
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anteriorcolumn or horns
posterior column or horns
lateral gray column or horn (THORACIC AND
LUMBER)
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united by
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gray commissure
With central canal
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Nerves cell groups in the anterior
gray column
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Alpha efferent
nerve
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large
Multipolar
It innervates the skeletal
muscle
Axon pass out in
anterior roots of spinal
nerves
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Gamma efferent
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Small
Multipolar
It innervates intrafusal
muscle fibers of
neuromuscular spindles
Axon may pass out in
anterior roots of the
spinal nerves
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Nerve cell of the anterior gray column
is divided into three basic groups
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(1) MEDIAL GROUP
(2) CENTRAL GROUP
(3) LATERAL GROUP
Medial group
EXTENTION
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WHOLE SPINAL CORD
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innervate
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muscle of
neck,
trunk,
intercostal
abdominal
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(2)Central group:
EXTENTION
cervical, lumber, sacral segments
Three nuclei
(a) phrenic nucleus
(C3’4’5)
INERVATE
DIAGHPHRAM
(b)
accessory nucleus)
(C5 OR 6)
INNERVATION
sternocliedomastoid and trapezius muscle
(c) lumbosacral nucleus
(L2 TO S1)
INNERVATION
unknwon distribution
Lateral group
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Extention
cervical and lumbosacral segment
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Innervation
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Muscles
(1) upper limb
(2) lower limb
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Nerve cells of the posterior gray
column
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four nerve cell group
1 substantia gelatinosa
2 nucleus propius
3 nucleus dorsalis (clarks column)
4 visceral afferent nucleus
First two
extention
through out the length of the cord
other two
extention
lumber and thoracic segments
Substantia gelatinosa
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location
apex of the posterior gray column
composed
Golgi type 2 neuron
function
receives afferent fiber associated with
pain ,
temperature
touch.
Furthermore it receive input from the descending
fibers from the supraspinal level .
Nucleus propius
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Location
Below s g
Function
senses of
position
movement (proprioception)
two points discrimination
vibration
Nucleus dorsalis
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Location
base of the posterior gray column
extending
C8 to L3 4
FUNCTION
proprioceptive endings
neuromuscular spindles and tendon
spindle
Visceral afferent nucleus
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LOCATION
lateral to the nucleus dorsalis
EXTENTION
T1 to L2
FUNCTION
receiving visceral afferent information
Nerve cell group lateral gray column
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Extend
T1 TO S4
Cells
T1 TO L3
preganglionic sympathetic nerve fiber
CELLS
S 2,3,4
preganglionic parasympathetic
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fiber
The gray commissure and central
canal
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LOCATION
the anterior and posterior gray columns on each side are connected by
a transverse gray commissure so that the gray column r in the central
of the gray commissure is situated central canal.
Superiorly
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above this it open into the cavity of the fourth ventricle
continuous with the central canal of the caudal half of the medulla
oblongata
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Inferiorly
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It is closed
conus medullaris it expend into the fusiform terminal ventricle
terminate below with in the root of the filum terminale
It is filled with cerebrospinal fluid and is lined with epithelium called
the ependyma
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IT resembles letter H
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posterior gray commissure
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The part of the gray commissure that is
situated posterior gray canal
Anterior gray commisure
lie anterior to the canal
White mater
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It is divided into
anterior lateral
posterior white columns or finiculi.
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anterior column
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location
lie on each side lie in between the midline and the point of emergence
of the anterior nerve root .
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lateral column
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location
between the emergence of the anterior nerve root and the entry of the
posterior nerve root the
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posterior column
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location
in between the entry of posterior nerve root and midline
Structure
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composition
in centrral nervous system the white mater of spinal
cord consist of a mixture of
nerve fiber
neuroglia
blood vessel
it surrounds the gray mater
its white color is due to the high proportion of
myelinated nerve fiber
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Blood Supply of the Spinal Cord
The spinal cord receives its arterial supply from three
small, longitudinally running arteries: the two
posterior spinal arteries and one anterior spinal
artery. The posterior spinal arteries, which arise
either directly or indirectly from the vertebral arteries,
run down the side of the spinal cord, close to the
attachments of the posterior spinal nerve roots. The
anterior spinal arteries, which arise from the vertebral
arteries, unite to form a single artery, which runs
down within the anterior median fissure.
The posterior and anterior spinal arteries are
reinforced by radicular arteries, which enter the
vertebral canal through the intervertebral foramina.
The veins of the spinal cord drain into the internal
vertebral venous plexus.
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INJURIES
Injuries in children
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Children account for 1-10% of all spinal
injuries.
Motor vehicle accidents account for most
injuries, followed by falls and sports.
Most serious spinal injuries in children involve
the cervical spine.
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In children less than 8 years of age, most
injuries are between the occiput and C2:
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Fulcrum of movement located at C2-3 in children,
C5-6 in adults
Significant ligamentous and joint capsule laxity
Relatively large head and weak neck muscles
Horizontal orientation of facet joints
Incomplete ossicification of odontoid process
Injuries in
adults
Terminology
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Plegia = complete lesion
Paresis = some muscle strength is preserved
Tetraplegia (or quadriplegia)
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Paraplegia
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Injury of the cervical spinal cord
Patient can usually still move his arms using the segments
above the injury (e.g., in a C7 injury, the patient can still
flex his forearms, using the C5 segment)
Injury of the thoracic or lumbo-sacral cord, or cauda equina
Hemiplegia
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Paralysis of one half of the body
Usually in brain injuries (e.g., stroke)
What are the differences between
UMN and LMN? (e.g., cauda equina
vs. myelopathy)
Thoracic injuries (T2-L1)
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Paraparesis or paraplegia
UMN (upper motor neuron) signs
Cauda equina injuries (L2 or
below)
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Paraparesis or paraplegia
LMN (lower motor neuron) signs
Thigh flexion is almost always preserved to
some degree
What is the difference between
cauda equina and conus medullaris
syndrome?