Vertebral Column Flashcards
what is a primary curvature?
an anterior concavity
what is a secondary curvature?
a posterior concavity
what is an anterior concavity vs a posterior concavity?
anterior = concavity at the body of the vertebra
posterior = concavity at the spinous process of the vertebra
As development occurs, where are primary curvatures located?
thoracic region
sacral region
as development occurs, where are the secondary curvatures located?
cervical region
lumbar region
what element of the vertebral column holds the majority of the weight? How much does it hold?
vertebra body
75-80%
what is the pedicle?
a bilateral, tubular structure that protrudes from the body posteriorly
what is important about the pedicle? when stacked, what do the pedicles form?
there are superior and inferior notches that when stacked form the intervertebral foramen.
what exits from the intervertebral foramen?
spinal nerves
what are the laminae?
bilateral, obliquely oriented structures that lead to the spinous processes
how do spinous and transverse processes differ?
spinous - points posteriorly
transverse - points laterally from laminae/pedicles
what structure supports a minority of a person’s body weight? How much does it hold?
Articular processes
20-25%
How many cervical vertebra are there?
7
What is kyphosis? what type of curvature is that?
excess curvature in the thoracic region
1st degree
what is lordosis? what type of curvature is that?
excess curvature in the lumbar region
2nd degree
what is scoliosis?
a lateral deviation, typically due to a missing/extra portion of vertebra
of the 33 vertebral elements, how many are moveable vs immoveable?
moveable = 24
immoveable = 9
how many cervical vertebrae are there?
7
what is different about CV1?
no spinous process or vertebral body
What is an inferior vertebra named in relation to the superior?
atlas = superior
axis = inferior
what is the odontoid process? (Dens)
what does it allow for?
the vertebral body of CV2
acts as a stable pivot that allows for lateral rotation of the head
what is the main action between CV1 and the skull?
flexion and extension
what are the characteristics of all cervical vertebrae?
bifid spinous process
nearly horizontal articular processes
transverse foramen
what is a bifid spinous process?
what is the downside of having nearly horizontal articular processes?
there is a greater chance of slippage that could in turn sever the spinal cord
what purpose does the transverse foramen serve in the cervical region?
allows for the vertebral artery to pass through up to the brain
what vertebrae does the vertebral artery pass through in the cervical region?
CV6 to CV1
what is significant about CV7?
it has the first prominent spinous process
what is the name of the significance at CV7?
vertebra prominens
what motions are permitted at the cervical vertebrae?
flexion, extension, lateral flexion and rotation
How many vertebrae are there in the thoracic region?
12
what is interesting about TV1-4? what is interesting about TV9-12?
more like cervical vertebrae and more like lumbar vertebrae
what are the characteristics of the thoracic vertebra?
long, sharp, oblique spinous processes
vertical articular processes
how do ribs 1-10 articulate with thoracic vertebrae?
head of the rib articulates with the body and the transverse process
how do ribs 11 & 12 articulate with the thoracic vertebra?
the head of the rib articulates with the body of the vertebra itself.
how does the number of the thoracic vertebra relate to the number of the ribs?
they are the same, TV1 = Rib 1
how is the articular process of the thoracic vertebrae different than that of the cervical vertebrae in the transverse plane?
Thoracic = vertical articular processes
cervical = horizontal articular processes
what movements are possible at the thoracic vertebrae?
flexion, extension, lateral flexion and rotation.
how are the degrees of movement different between cervical and thoracic vertebrae? what causes this?
thoracic is more limited because of relatively thin intervertebral discs whereas cervical is more free due to relatively thicker intervertebral discs.
how do elements of lumbar vertebrae differ from the other regions?
larger bodies
larger intervertebral foramen
block-like spinous processes
vertically oriented articular processes
what motions are allowed in the lumbar region? what isn’t? why is that?
flexion and extension are fairly free, but rotation is limited.
more stability = less freedom of movement
what is different about the sacral region compared to the other 3?
immovable, fused elements
what are the holes in the sacral region?
sacral foramina
what structure can pass through the anterior sacral foramina?
ventral rami
what structure can pass through the posterior sacral foramina?
dorsal rami
what main structure does the sacrum articulate with?
ilium of os coxae
what is the sacral hiatus? what passes through this structure? why is it important?
a gap at the inferior portion of the sacrum. the coccygeal nerve exits this structure allowing the epidural space to be accessed.
what are intervertebral discs?
fibrocartilaginous structures that form symphysis joints
how much of the vertebral column do the intervertebral discs count for?
1/4 the length
what is the nucleus pulposus?
central region of the intervertebral disc
what is the nucleus pulposus derived from / made of?
derived from the embryonic notochord
primarily water
what is the annulus fibrosis?
concentric rings of fiber that surround the nucleus pulposus
how much of the intervertebral disc is comprised of water? what happens to that as we age?
80 %
the water content decreases and becomes more fibrous which means it is more susceptible to compression and rupturing
what causes a herniated disc? which direction of herniation causes nerve impingement?
rupture of the annulus fibrosis causes the nucleus pulposus to herniate in any direction.
posteriorly or posterior laterally
what is the anterior longitudinal ligament?
a broad ligament that covers the anterior aspect of the vertebral body
what is the posterior longitudinal ligament?
a less broad ligament that covers the posterior aspect of the vertebral body anterior to the spinal cord
what is the ligamentum flavellum?
a dense, yellowish structure that connects the adjacent lamina
how long are the anterior and posterior longitudinal ligaments?
the entire length of the vertebral column
what is the supraspinous ligament?
ligament that covers the posterior aspect of the spinous process
what is the interspinous ligament?
a segmented ligament that holds adjacent spinous processes together.
which ligaments are full-length? which ligaments are segmented?
full - anterior longitudinal, posterior longitudinal, supraspinous
segmented - ligamentum flavum, interspinous
what is in the epidural space?
fat and internal vertebral venus plexus
how does the internal venus plexus communicate with the external venus plexus?
veins that run through intervertebral foramen and veins that pass through the bones of vertebral elements.
what is the cause of sciatica?
posterolateral herniation of nucleus pulposus causing pressure on the spinal nerve in the vertebral foramen.
what is in the subarachnoid space?
cerebrospinal fluid
what forms the intervertebral foramen?
superior/inferior notches of the pedicles
intervertebral discs
articular processes
how does herniation affect the spinal nerve of adjacent vertebra?
herniation in a vertebra affects the spinal nerve of an inferior vertebra
how do spinal nerves exit lumbar intervertebral foramen vs cervical?
lumbar = nerve exits below the vertebra
cervical = nerve exits above the vertebra
what information do dorsal and ventral roots provide the nervous system?
dorsal - sensory
ventral - motor
what does the junction of the dorsal/ventral root signify?
the beginning of the spinal nerve
what does the dorsal root ganglion contain?
sensory cell bodies
what is a ramus?
a branch of the spinal nerve
