Anatomy of the spinal cord and spinal nerves
questions with verified answers
-What are the major blood supplies to the spinal cord?
What if there is a blockage to these arteries? Ans✓✓✓In this image see
the anterior and posterior (supplies post spinal cord) spinal arteries
again. One anterior, two posterior. Can see little branches that have now
perforated through into the spinal cord supplying the white matter and
the gray matter
-If look at anterior spinal artery, its supplying about 2/3rds of the volume
of the spinal cord at each segment. Have branches going quite deep into
the gray matter, to the ventral horn so can see how important they are.
If have blockage or damage to these arteries esp. the major starting
points of the anterior spinal artery, that could cause an ischemia/infarct
of an area like the yellow circle, lack of blood flowing to this area,
which can cause cell death in the ventral horn, so could lose the cell
bodies of the motor neurons here, they could die as a result of not
receiving blood from the anterior spinal artery.
Also the segmental arteries which are anastoming here with the anterior
spinal artery, and also sending their own little branches into the spinal
cord. Segmental arteries are just helping to augmnet/supplement that
blood supply
-Great radicular artery, important for supplying the lower spinal cord
Damage to this artery compromises perfusion and may result in
paraplegia (functional motor loss of lower limb, so complete paralysis of
either limb)
Does the spinal cord match up to the vertebrae exactly? Ans✓✓✓The
spinal cord isnt matching up to the alignment of the vertebrae and thats
,because the vertebrae grow much quicker than spinal cord does as
develop, means there is a mismatch.
To make up for that have got all of these rootlets that will stretch from
the spinal cord to meet eventually the right exit point, the right opening
where theyll emerge and go to where they need to go.
FLIP FOR Q.
Spinal cord with meninges retracted. Seeing rootlets emerging from
what looks like the anterior aspect. Can see some dorsal rootlets and
ventral rootlets. Can see where dorsal and ventral rami might be. Spinal
nerve not visible, off picutre through the IV foramen. Ans✓✓✓What
does this image show?
, FLIP FOR Q. Ans✓✓✓Where is the spinal cord in this cross section?
How many pairs of spinal nerves?
And for each region how many? And levels? Ans✓✓✓31
-8 cervical (C1-C8)
-12 thoracic (T1-T12)
-5 lumbar (L1-L5)
-5 sacral (S1-S5)
-1 coccygeal (Co1)
Each spinal cord segment gives rise to 1 pair of segmental spinal nerves
What are dermatomes? Ans✓✓✓-Due to sensory innervation of the
skin.
-Image shows dermatome map
-Able to see from this map potential areas where could have innervation
from just one spinal nerve, two regions of the skin
-An area of skin innervated by just one spinal nerve
-This pic shows C6. Early spinal cord, neural tube which as forms in the
embryo, spinal nerves form beside and dragged out into dev. limb which
starts as a small bud at level of shoulder then stretches out. Thats how go
from having a very segmented pattern on side of body for dermatomes to
something much more stretched out and elaborate eg the dermatome
pattern of upper limb
-C6 ends at thumb, c6 thumbs up
questions with verified answers
-What are the major blood supplies to the spinal cord?
What if there is a blockage to these arteries? Ans✓✓✓In this image see
the anterior and posterior (supplies post spinal cord) spinal arteries
again. One anterior, two posterior. Can see little branches that have now
perforated through into the spinal cord supplying the white matter and
the gray matter
-If look at anterior spinal artery, its supplying about 2/3rds of the volume
of the spinal cord at each segment. Have branches going quite deep into
the gray matter, to the ventral horn so can see how important they are.
If have blockage or damage to these arteries esp. the major starting
points of the anterior spinal artery, that could cause an ischemia/infarct
of an area like the yellow circle, lack of blood flowing to this area,
which can cause cell death in the ventral horn, so could lose the cell
bodies of the motor neurons here, they could die as a result of not
receiving blood from the anterior spinal artery.
Also the segmental arteries which are anastoming here with the anterior
spinal artery, and also sending their own little branches into the spinal
cord. Segmental arteries are just helping to augmnet/supplement that
blood supply
-Great radicular artery, important for supplying the lower spinal cord
Damage to this artery compromises perfusion and may result in
paraplegia (functional motor loss of lower limb, so complete paralysis of
either limb)
Does the spinal cord match up to the vertebrae exactly? Ans✓✓✓The
spinal cord isnt matching up to the alignment of the vertebrae and thats
,because the vertebrae grow much quicker than spinal cord does as
develop, means there is a mismatch.
To make up for that have got all of these rootlets that will stretch from
the spinal cord to meet eventually the right exit point, the right opening
where theyll emerge and go to where they need to go.
FLIP FOR Q.
Spinal cord with meninges retracted. Seeing rootlets emerging from
what looks like the anterior aspect. Can see some dorsal rootlets and
ventral rootlets. Can see where dorsal and ventral rami might be. Spinal
nerve not visible, off picutre through the IV foramen. Ans✓✓✓What
does this image show?
, FLIP FOR Q. Ans✓✓✓Where is the spinal cord in this cross section?
How many pairs of spinal nerves?
And for each region how many? And levels? Ans✓✓✓31
-8 cervical (C1-C8)
-12 thoracic (T1-T12)
-5 lumbar (L1-L5)
-5 sacral (S1-S5)
-1 coccygeal (Co1)
Each spinal cord segment gives rise to 1 pair of segmental spinal nerves
What are dermatomes? Ans✓✓✓-Due to sensory innervation of the
skin.
-Image shows dermatome map
-Able to see from this map potential areas where could have innervation
from just one spinal nerve, two regions of the skin
-An area of skin innervated by just one spinal nerve
-This pic shows C6. Early spinal cord, neural tube which as forms in the
embryo, spinal nerves form beside and dragged out into dev. limb which
starts as a small bud at level of shoulder then stretches out. Thats how go
from having a very segmented pattern on side of body for dermatomes to
something much more stretched out and elaborate eg the dermatome
pattern of upper limb
-C6 ends at thumb, c6 thumbs up
