SPINAL CORD
We distinguish two portions of the CNS
one contained in the cranial box (the encephalon)
one contained in the vertebral canal (medulla)
FUNCTIONS
represents a center of integration
o bundles of white matter fibers pass through it
connect the various segments of the medulla
we will speak of intersegmental integration bundles
o allows the encephalon to receive sensitive information (ascending bundles)
o exerts control through the encephalon via efferent fibers (descending bundles)
With somatic motor neurons on the musculoskeletal side
With visceral motor neurons on the visceral part
DELIMITATIONS
Superior
o from the superior margin of the atlas (first cervical vertebra)
o is the continuum of the brainstem located in the skull
Inferior
o It ends with a portion called CONUS MEDULLARIS
between L1 and L2 (intervertebral disc)
From the medullary cone it continues through the FILUM TERMINALE
a thin median filament
The filum is flanked by the CAUDA EQUINA (“horse tail”)
Nerve roots with vertical course up to sacrum and coccyx
MORPHOLOGY
Slightly cylindrical shape, flattened in a latero-lateral sense
Presents two bulges (greater nerve demand for AI and AS)
o CERVICAL bulge C2-D2 (neuromeres for upper limb)
o LUMBAR bulge D10-L2 (neuromeres for lower limb)
It is composed
o centrally by the gray substance (bodies of neurons)
from which sensitive fibers enter and motor fibers exit
o peripherally by the white substance (axons of neurons)
MENINGES
Membranes that wrap around the entire CNS (encephalon and medulla)
They are 3 (in order from outside to inside)
o Dura mater
o Arachnoid mater
o Pia mater
FUNCTIONS
, to secure and protect the medulla
o from mechanical insults derived from vertebral movements and ligamentous tensions
o aided by cerebrospinal fluid and epidural fat
provide support to the vascular part
DURA MATER (outermost layer)
separated from the bone by the EPIDURAL or PERIDURAL SPACE
represents the most resistant envelope
In its course it presents itself
o cranially
with considerable bony insertions as it is strongly adherent
o at medullary level
is free to ensure the movement of the vertebrae
with the exception of
first three cervical vertebrae (C1, C2, C3)
at the level of the sacrum (S1, S2, S3)
EPINEVRIUM
o o sleeve consisting of dura mater and arachnoid
o accompanies the spinal nerve root to the exit of the conjugation hole
o in the outermost area the dura mater fuses with the outermost layer of the nerve
ARACNOID (intermediate layer)
owes its name to the fact that from a histological point of view it has a spider web shape
located under the dura mater
supporting function of the vascular part
Between the dura mater and the arachnoid there is a virtual space called SUBDURAL SPACE
PIA MADRE (deepest layer)
very thin veil that faithfully envelops the entire medullary formation
creeping even in the grooves present in the marrow
rich in arterial and venous vessels
sends towards the marrow 22 triangular processes (DENTICULAR LINKS)
o laterally expanding pial expansions
o anchor the pia to the arachnoid and dura
o important means of fixation of the medulla
between the arachnoid and the pia mater is the SUBARACNOID SPACE
occupied by cerebrospinal fluid (or cephalorachidian fluid)
o it also presents
at the center of the medulla in the ependymal canal
and peripherally in the subarachnoid space
VASCULARIZATION
ARTERIES
There are two arterial systems
Extramedullary system (consisting of the radicular arteries)
o Vascularize
the outer part of the medulla
We distinguish two portions of the CNS
one contained in the cranial box (the encephalon)
one contained in the vertebral canal (medulla)
FUNCTIONS
represents a center of integration
o bundles of white matter fibers pass through it
connect the various segments of the medulla
we will speak of intersegmental integration bundles
o allows the encephalon to receive sensitive information (ascending bundles)
o exerts control through the encephalon via efferent fibers (descending bundles)
With somatic motor neurons on the musculoskeletal side
With visceral motor neurons on the visceral part
DELIMITATIONS
Superior
o from the superior margin of the atlas (first cervical vertebra)
o is the continuum of the brainstem located in the skull
Inferior
o It ends with a portion called CONUS MEDULLARIS
between L1 and L2 (intervertebral disc)
From the medullary cone it continues through the FILUM TERMINALE
a thin median filament
The filum is flanked by the CAUDA EQUINA (“horse tail”)
Nerve roots with vertical course up to sacrum and coccyx
MORPHOLOGY
Slightly cylindrical shape, flattened in a latero-lateral sense
Presents two bulges (greater nerve demand for AI and AS)
o CERVICAL bulge C2-D2 (neuromeres for upper limb)
o LUMBAR bulge D10-L2 (neuromeres for lower limb)
It is composed
o centrally by the gray substance (bodies of neurons)
from which sensitive fibers enter and motor fibers exit
o peripherally by the white substance (axons of neurons)
MENINGES
Membranes that wrap around the entire CNS (encephalon and medulla)
They are 3 (in order from outside to inside)
o Dura mater
o Arachnoid mater
o Pia mater
FUNCTIONS
, to secure and protect the medulla
o from mechanical insults derived from vertebral movements and ligamentous tensions
o aided by cerebrospinal fluid and epidural fat
provide support to the vascular part
DURA MATER (outermost layer)
separated from the bone by the EPIDURAL or PERIDURAL SPACE
represents the most resistant envelope
In its course it presents itself
o cranially
with considerable bony insertions as it is strongly adherent
o at medullary level
is free to ensure the movement of the vertebrae
with the exception of
first three cervical vertebrae (C1, C2, C3)
at the level of the sacrum (S1, S2, S3)
EPINEVRIUM
o o sleeve consisting of dura mater and arachnoid
o accompanies the spinal nerve root to the exit of the conjugation hole
o in the outermost area the dura mater fuses with the outermost layer of the nerve
ARACNOID (intermediate layer)
owes its name to the fact that from a histological point of view it has a spider web shape
located under the dura mater
supporting function of the vascular part
Between the dura mater and the arachnoid there is a virtual space called SUBDURAL SPACE
PIA MADRE (deepest layer)
very thin veil that faithfully envelops the entire medullary formation
creeping even in the grooves present in the marrow
rich in arterial and venous vessels
sends towards the marrow 22 triangular processes (DENTICULAR LINKS)
o laterally expanding pial expansions
o anchor the pia to the arachnoid and dura
o important means of fixation of the medulla
between the arachnoid and the pia mater is the SUBARACNOID SPACE
occupied by cerebrospinal fluid (or cephalorachidian fluid)
o it also presents
at the center of the medulla in the ependymal canal
and peripherally in the subarachnoid space
VASCULARIZATION
ARTERIES
There are two arterial systems
Extramedullary system (consisting of the radicular arteries)
o Vascularize
the outer part of the medulla
