GROSS APPEARANCE OF SPINAL CORD
• The spinal cord is roughly cylindrical shape
• it begins superiorly at the foramen magnum in the skull where, it is
continuous weather medulla oblongata of brain and it terminates
inferiorly in the adult at level of lower border of the first lumber vertebra
• in the young child, it is relatively longer and usually ends at the upper
border of the 3rd lumber vertebra
• Thus, it occurs and occupies the upper 2/3 of vertebral canal of the
vertebral column and surrounded by three meninges, the dura mater,
the arachnoid mater, and the pia mater…
• Further protection is provided by cerebrospinal fluid with surrounds the
spinal cord in sub arachnoid space
• In cervical region where it is gives origin to brachial plexus and in the
lower thoracic and lumber regions, where origin of lumbosacral plexus,
the spinal cord is fusiformly enlarged
• the enlargements are referred to as the cervical and lumber
enlargements
• inferiorly , the spinal cord, tapers off into conus medullaris, from the
apex of which a prolongation of pia mater, the filum terminale,
descends to be attached to the posterior surface of coccyx
• The cord possesses A deep longitudinal fissure called anterior median
fissure in the midline anteriorly and a shallow furrow called the
posterior median sulcus on the posterior surface
• along the entire length of spinal cord are attached 31 pairs Of spinal
nerves by anterior or motor roots and posterior or sensory roots
, • Each route is attached to cord by a series of rootlets, which extend the
whole length of the corresponding segment of cord.
• each posterior nerve root possesses a posterior root ganglion, the cells
of which give rise to peripheral and central nerve fibres
Structure of spinal cord :
• the spinal cord is composed of inner core of grey matter with
surrounded by an outer covering of white matter
• there is no indication that the cord is segmented.
GRAY MATTER :
• Gray matter on the cross section the gray matter is seen as H - shaped
pillar with anterior and posterior gray columns or horns united by a thin
grey commissure containing the small central canal
• A small lateral grey column or horn is present in thoracic or upper
lumbar segments of the cord
• The amount of gray matter present at any given level of spinal cord is
related to amount of muscles innervated at that level
• Thus, its size is greatest within the cervical or lumbosacral
enlargements of cord, which innervate the muscles of upper and lower
limbs
Structure
• as in other regions of central nervous system, the gray matter of spinal
cord consists of mixture of nerve cells and their processes, neuroglia
and blood vessels
• The nerve cells are multipolar and the neuroglia forms an intricate
network around the nerve cell bodies and their neurites
Nerve cell groups in ANTERIOR GRAY COLUMNS :
• Most nerve cells are large and multipolar and their axons pass out in
anterior roots of spinal nerves as alpha efferents , which innervates
skeletal muscles
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• The spinal cord is roughly cylindrical shape
• it begins superiorly at the foramen magnum in the skull where, it is
continuous weather medulla oblongata of brain and it terminates
inferiorly in the adult at level of lower border of the first lumber vertebra
• in the young child, it is relatively longer and usually ends at the upper
border of the 3rd lumber vertebra
• Thus, it occurs and occupies the upper 2/3 of vertebral canal of the
vertebral column and surrounded by three meninges, the dura mater,
the arachnoid mater, and the pia mater…
• Further protection is provided by cerebrospinal fluid with surrounds the
spinal cord in sub arachnoid space
• In cervical region where it is gives origin to brachial plexus and in the
lower thoracic and lumber regions, where origin of lumbosacral plexus,
the spinal cord is fusiformly enlarged
• the enlargements are referred to as the cervical and lumber
enlargements
• inferiorly , the spinal cord, tapers off into conus medullaris, from the
apex of which a prolongation of pia mater, the filum terminale,
descends to be attached to the posterior surface of coccyx
• The cord possesses A deep longitudinal fissure called anterior median
fissure in the midline anteriorly and a shallow furrow called the
posterior median sulcus on the posterior surface
• along the entire length of spinal cord are attached 31 pairs Of spinal
nerves by anterior or motor roots and posterior or sensory roots
, • Each route is attached to cord by a series of rootlets, which extend the
whole length of the corresponding segment of cord.
• each posterior nerve root possesses a posterior root ganglion, the cells
of which give rise to peripheral and central nerve fibres
Structure of spinal cord :
• the spinal cord is composed of inner core of grey matter with
surrounded by an outer covering of white matter
• there is no indication that the cord is segmented.
GRAY MATTER :
• Gray matter on the cross section the gray matter is seen as H - shaped
pillar with anterior and posterior gray columns or horns united by a thin
grey commissure containing the small central canal
• A small lateral grey column or horn is present in thoracic or upper
lumbar segments of the cord
• The amount of gray matter present at any given level of spinal cord is
related to amount of muscles innervated at that level
• Thus, its size is greatest within the cervical or lumbosacral
enlargements of cord, which innervate the muscles of upper and lower
limbs
Structure
• as in other regions of central nervous system, the gray matter of spinal
cord consists of mixture of nerve cells and their processes, neuroglia
and blood vessels
• The nerve cells are multipolar and the neuroglia forms an intricate
network around the nerve cell bodies and their neurites
Nerve cell groups in ANTERIOR GRAY COLUMNS :
• Most nerve cells are large and multipolar and their axons pass out in
anterior roots of spinal nerves as alpha efferents , which innervates
skeletal muscles
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