What are the 5 regions of the vertabral column?
cervical
thoracic
lumbar
sacral
coccyx
Which are the primary curvatures and when do they develop? Which are the secondary curvatures and when do they develop?
THe primary curvatures are the thoracic and sacral - they develop in the fetus.
THe secondary curvatures are convex and include the cervical and lumbar. They develop as an individual ages and assumes the upright posture
What happens in kyphosis?
the cervical curvature is accentuated = dowager hump
What happens in lordosis?
a genetic accentuation of the lumbar curvature
What happens in scoliosis?
lateral curvature of the vertebral column
Identify the parts…..
What pathology can occur as the bones of the vertebrae become more porous?
osteoporosis develops and this can cause the vertebrae to compress = compression fractures
What is the special name of the C1 vertebra?
WHat is the name of the C2 vertebra?
C1 = atlas
C2 = Axis
What is special about the structure of C1 and C2?
The transverse processes of these vertebrae have foramen them in - the transverse foramen– through which the vertebral artery passes
THe other unique thing is that the atlas doesn’t have a body. It’s fused with the body of the axis to form the dens of the axis.
THere is a synovial joint over the dens that permits the rotation of the head on the vertebral column
What artery flows through the transverse foramen?
the vertebral artery - it does NOT pass through the transverse foramen of C7, even though it has one
What is the dense connective tissue that spans from C7 up to the occipital bone?
the ligamentum nuchae
What is the deep muscle of the back that is innervated by the dorsal rami of the spinal nerves?
the erector spinae
what does the erector spinae do?
it extensors of the trunk - especially the neck and back
What are the three vertebral ligaments?
anterior and posterior longitudinal ligaments (located on anterior and posterior surfaces of the vertebral bodies
ligamentum flavum (between the laminae of adjacent vertebrae)
interspinous ligament (between spines of adjacent vertebrae)
What is the space between the dura and the bone of the vertebral canal called? What two things are located inside?
The epidural space. It is filled with epidural fat and a venous plexus known as the internal vertebral plexus of beins
What is unique about the veings in the internal vertebral plexus?
they do NOT HAVE VALVES. This means blood can flow in either direction of these vessels.
How are the plexus veings connected to the veins outside the vertebral column?
they go thorugh the intervertebral foramen.
What is the tough outer covering that encloses the spinal cord?
the dura mater
What separates the dura from the vertebral column?
the epidural space
As the dura continues through the intervertebral foramen, it surrounds the spinal nerve and is continuous with what structure?
the epineurium that surrounds the nerve
What are the lines pointing to?
the anterior sacral foramina
the ventral rami of sacral spinal nerves exit through these
What are the arrows pointing to?
black arrows - posterior sacral foramina
(the dorsal rami exit through these)
red - sacral hiatus
What membrane lies directly beneath the dura in a living individual?
the arachnoid membrane
What separates the arachnoid from the pia mater? What’s inside?
the subarachnoid space filled with CSF
What is the pia attached to?
the pia is intimately attached to the spinal cord
what do the denticulate ligaments do for the pia?
the denticulate ligaments are formed by the pia and extend from the spinal cord to pierce through the arachnoid membrane and attach to the dura
At what level does the spinal cord end within the vertebral canal? What is this called?
It usually stops at L2 in the conus medullaris
After the conus medullaris, the pia mater extends to become what?
the internal medullary filum, which will then fuse with the arachnoid and dura around S2
When the internal medullary filum fuses with the arachnoid and dura at S2, they continue on as the what? What does it attach to?
They continue on as the external medullary filum, or coccygeal ligament which attaches to the coccyx.
After the spinal cord ends, what is the subarachnoid space with its CSF called?
the lumbar cistern
What occupies the lumbar cistern besides CSF?
the cluster of lumbar and sacral spinal nerves called the cauda equina.
Where are the dorsal root ganglia located in relation to the vertebral column?
they are either near or in the intervertebral foramen
What does the intervertebral disc consist of?
WHat is the outermost covering called? What is the core called?
It’s make of fibrocartilage
the outermost covering of the disc is the annulua fibrosus, which is dense connective tissue
the core is the nucleus pulposus, which is a jelly-like substance
What happens in disc herniation?
pressure is placed on the intervertebral disc
if ther eis too much pressure, the annulus fibrosis will rupture and the nucleu pulposus will herniate out
Where is the weak point of the intervertebral discs/where does herniation typically occur?
there is a weak point just adjacent to the posterior longitudinal ligaments, just above the pedicles
In a lumbar puncture, what landmark do you use and where do you insert the needle?
you can find the region of L4 as a landmark by drawing a horizontal line from the tops of the iliac crests on both sides
you insert the needle between the L3 and L4 spinous processes.
Where does the CSF come from in a spinal tap?
in the subarachnoid space
Where do they put anesthesia if they’re doing a spinal nerve block?
the subarachnoid space
Why do they typically administer a spinal block with the patient angled up?
they don’t want the anesthesia to reach too high up the spinal cord - you could paralyze the diaphragm
If herniation of 4th lumbar intervertebral disc occurs, what spina nerve is effected? WHere will this cause pain?
Herniation of the L4 intervertebral disk will put pressure on the L5 spinal nerve. This causes pain to radiate into the back and down the lower extremity into the dorsum of the foot.
If the L5 intervertebral disc herniates, what nerve is affected and where does the patient experience pain?
If the L5 intervertebral disc hernaites, pressure is put on the S1 spinal nerve. This causes pain to radiate into the lower back and down the back of the lower extremity to the lateral side of the foot.
Besides pain, what will happen to the LE if the S1 spinal nerve is compressed?
plantar flexion of the foot and great toe reduced - can’t walk on toes
atrophy of the calf muscle
absent ankle jerk reflex
What will happen if the L4 disc protrudes MEDIALLY?
You can have pressure on L5 and it may possible affect S1-4 as well
medial protrusion is rarer because of the additional support to the intervertebral disc by the posterior longitudinal ligament