Main structures of the back Flashcards
To be able to identify the different structures in the back
what are the pedicles?
they are the bridge between the vertebral body and the transverse process. they form the edges of the vertebral canal/foramen.
what are the laminae?
lamina refer to the smooth surfaces on either side of the spinous process that fuse into the rest of the vertebral arch.
what are the transverse processes?
they are the projections that point east-west, left and right on both sides of the vertebrae.
what are the anterior and posterior turbercles of the cervical spine?
They are two round projections that are found on the cervical transverse processes. They stick out of the transverse foramen, and the one on top is anterior and the one below is posterior.
what is the transverse foramen? (cervical spine)
the transverse foramen are two bony holes within the transverse foramen. it is home to important blood vessels like the carotid arteries that send blood from the heart to the brain. thus they must be protected by a bony tunnel.
what are the spinous processes?
It is the large projection at the back of the vertebral body, between the two transverse processes. It points downwards in the thoracic spine, points outwards and is bifid (split in two) in the cervical spine and is short and fat in the lumbar spine.
what is the vertebral foramen and what is its relationship to the vertebral canal?
The vertebral foramen is the name of the hole within a single vertebrae where the spinal chord runs through. When there are multiple vertebrae on top of each other to form the column, these holes join together to form a tunnel, or a canal.
what are the two atypical cervical vertebrae and what makes them different?
C1- is the atlas. It has no vertebral body, and instead has a larger vertebral foramen. It also has two sulci, or grooves along the posterior arch to house the vertebral arteries. C2- the axis. The axis has a smaller vertebral body, with a specialised structure on top called the dens. The dens is a cylindrical projection that articulates with the anterior arch of the atlas above it and together, allows sideways rotation of the neck (180 degrees). C7- has a very long spinal process that can be palpated at the back of the neck.
how many vertebrae are in the back?
33-34 vertebrae
how many vertebrae are in the cervical spine?
7
how many in the thoracic spine?
12
how many in the lumbar spine?
5
how many in the sacral spine?
5- but they fuse into 1 big bone at about age 18
how many in the coccyx?
3-5 individual bits, but they fuse into 1 big bone like the sacrum.
list the key features of the lumbar vertebra.
it has the largest vertebral body in the spine, and the vertebral body is oval in shape. The spinous process is short and flat, but upright. the pedicles are short and fat. The articular surfaces face the medial side and are in line with the sagittal plane. This allows forward and back, up and down flexion and extension.
list the key features of the thoracic vertebrae.
the thoracic vertebrae have demi facets on the dorsal (topside) and ventral (bottom side) of the vertebral body to allow articulation with the head of the ribs. They also form a second site for articulation with the ribs at the turbercles on the transverse processes. The thoracic articular facets are oriented in the coronal plane, to enable lateral flexion/extension. The thoracic vertebra has an triangular body. the spinal process is long, but points downwards and sits on top of the process below it. The vertebral body has a foramen on the top surface of the body to accomodate the basivertebral foramen.
list the key features of the cervical vertebrae (typical ones)
the cervical vertebrae has a long, outward pointing, bifid spinal process (meaning it is split in two). The transverse processes have two holes inside them called transverse foramen that house the carotid arteries of the head. The atlas and axis are modified pivot joints.
what is the intervertebral foramen and what does it contain?
The intervertebral foramen are two holes on the lateral sides of the vertebrae that are formed between the pedicles of the vertebrae above and the one below. The nerve roots leave the canal via the foramen, and continue as the spinal nerve into the periphery.
what is the intervertebral disc?
The intervertebral disc is made up of two parts, the outer fibrocartilage rings called the annulus fibrosus, which holds the two vertebral bodies together. Then there is the nucleus pulposus, which is the jelly like center, that acts as a shock and weight absorbing pad. they are thickest in the lumbar spine.
what is the atlanto-occipital joint?
It is where the bottom part of the skull articulates with the first vertebra (C1-atlas) in the spine. It is a bilateral pair of synovial joints.
what is the atlanto-axial joint?
This is where the atlas and the axis both meet. They do so and form synovial joints at three sites. The first two AA joints are on either side of the dens. On these two lateral sides there are rotatory joints that are structured like superior and inferior facet joints. Then, the third site is between the dens and the inside surface of the anterior arch of the atlas.
what is an uncinate or uncovertebral joint?
They are non-synovial joints found in the cervical spine. They are bony processes that grow upwards and form a ‘u’ shape on top of the cervical vertebrae. This enables the cervical vertebrae to stack on top of each other.
What are the alar ligaments?
They are ligaments are the first ligament that wraps around the dens, strapping it in sideways to the axis in the shape of a ‘Y’, so that it doesn’t fall posteriorally into the vertebral canal and stab the spinal chord.
what are the transverse ligaments?
They are the second pair of ligaments that cover the dens. By strapping accross from left to right and up and down in the shape of a cross.
it prevents the dens from too much extension backwards into the vertebral canal, impinging on the spinal chord.
where is the anterior longitudinal ligament located?
it is found on the anterior most side of the vertebral canal. It runs downwards, along the front side of the vertebral bodies and prevents against anterior shear forces and keeps the vertebral bodies in place.
where is the posterior longitudinal ligament located?
The posterior longitudinal ligament runs along the posterior side of the vertebral bodies, but inside the vertebral canal. It has special widened areas over the sides of the intervertebral disks, which supports them.
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where is the ligamentum flavum?
The ligamentum flavum is a ligament of the vertebral arch underneath the laminae. It is a u-shape ligament that connects the vertebral arch above to the one below. It leaves gaps at the ends of the arch, the pedicles, which form the intervertebral foramen.
where is the supraspinous ligament?
It is a long, thin ligament that runs parallel to the posterior and anterior longitudinal ligaments. The only difference is that it runs along the tips of the spinous processes.
where are the interspinous ligaments?
They are found underneath the spinous processes and they connect the bottom surface of one spinous process to the top surface of the one below.
where are the intertransverse ligaments?
They are found underneath the transverse processes and they connect the bottom surface of one transverse process to the top surface of the one below.
What is the vertebral notch?
The vertebral notch is the name for the curved outer surface of the pedicles, directly above and below the intervertebral foramen.
