Vertebral Column Osteology Flashcards
What is the function of the vertebral column?
The function of the vertebral column is to support trunk posture, allow trunk movement, transmit the weight of te head, neck, trunk, and upper limb to the lower limbs, and protects the spinal cord.
What is the axial skeleton comprised of?
The axial skeleton is comprised of the cranium, vertebral column, ribs, and the sternum.
How many cervical vertebrae are there?
There are 7 cervical vertebrae
How many thoracic vertebrae are there?
There are 12 thoracic vertebrae
How many lumbar vertebrae are there?
There are 5 lumbar vertebrae
How many sacral vertebrae are there?
There are 5 sacral vertebrae and are fused in adults to form the sacrum
How many coccygeal vertebrae are there?
There are 4 coccygeal vertebrae fuse in adults to form the coccyx
what is the lumbosacral angle?
The lumbosacral angle occurs at the junciton of the longs axes of the lumbar region of the vertebral column and the sacrum
Where in th column do vertebrae reach its maximum size?
The vertebrae reach maximum size jsut immediately superior to sacrum. This transfers weight to the pelvic girdle at the sacro-iliac joints.
What type of joint is articulated among the superior 25 vertebrae that facilitates the spines flexibility?
These joints are called zygapophysial (facet) joints.
What features do the typical vertebrae consist of?
The typical vertebra has
a) vertebral body
b) vertebral arch
c) seven processes
Describe the curvature in the different sections of the vertebral column
Cervical= lordosis (concave)
thoracic= kyphosis (convex)
lumbar = lordosis (concave)
sacral = kyphosis (convex)
Surface Anatomy of the Vertebral Column. What vertebra is the most evident superficially?
C7 spinous process is the most evident superficially and is hence called vertebra prominens.
List the surface anatomy of the cervical vertebrae.
Name the surface anatomy in this image.
What and where is the nuchal groove?
The nuchal groove is a groove between your neck muscles where you may be able to feel the short bifid spinous processes of the C3-C5 vertebrae.
What is the medial longitudinal furrow?
This is the groove that runs the length of your back and is what the thoracic vertebrae lie deep to.
How can you identify T12 spinous process?
You can identify T 12 spinous process by palpating the short 12th rib which joins to the T12 vertebrae.
What vertebrae is the largest and carries the weight of the whole upper body?
L5 and is distinguished by its massive body and transverse processes. It is also very tall anteriorly and is responsible for the lumbosacral anlge
What is the triangular shape of the scarum a result of?
The triangular shape of the sacrum results from the rapid decreases in the size of the inferior lateral masses of the sacral vertebrae during development.
What is the pelvic girdle?
The pelvic girdle is the bony ring formed by the hip bones and sacrum, to which the lower limbs are attached.
What is the sacral canal?
It is a continuation of the vertebral canal in the sacrum
What has the sacral hiatus developed from and what does it represent?
The sacral hiatus is a result from absence of the laminae and spinous process of S5 and sometimes S4. The sacral hiatus leads into the sacral canal.
What is meant by the auricular surface of the sacrum?
The lateral surface of the sacrum looks like an auricle so it is called the auricular surface of the sacrum.
What vertebrae spinous process is identified by drawing a line from the highest points of the iliac crest landmarks?
The tip of the L4 spinous process is found when one draws a horizontal line between the highest parts of the iliac crests and is helpful when performing a CSF sample (spinal tap)
What spinous process is found within the horizontal line connecting the posterior superior iliac spines?
The S2 spinous process lies at the middle of a line drawn between the posterior superior iliac spines which form skin dimples.
what is the sacral triangle formed by?
The sacral triangle is formed from the two posterior superior ilian spines and the superior part of the intergluteal cleft.
Before maturity of the vertebral column what are the primary curvatures of the vertebral column?
1) thoracic
2) sacral
Of note, both of these are concave in the adult form of the vertebral column.
What are the secondary curvatures of the vertebral column?
a) cervical
b) lumbar
these are convex or lordosis curvatures in the adult vertebral column
What is the benefit of having curvature in the back?
The curvature of the back provides additional flexibility (shock-absorbing resilience) further augmenting that provided by the IV discs.
Name the features of the vertebra.
What are the identifying characteristics of the cervical vertebrae?
Body: small, wider side to side
Spinous process: short, bifid, projects posteriorly
vertebral foramen: triangular shaped
transverse process: has a foramina
superior and infereior articular processes: directed superoposteriorly
movements allowed: flexion & extension; lateral flexion; rotation
What runs through the foramen transversarium and what is their significance?
Arteries and veins pass through the transverse formina and the size of the transverse foramen is indicative of what level or section of the vertebral column that they are located in.
In what vertebrae is the cervical enlargement present?
The cervical enlargement can be seen in C3-C7 and as a result they have large vertebral foramina to accommodate this enlargement.
What is significant about the structure of the atlas (C1)?
The atlas or C1 does not have a spinous process or a vertebral body but ahs two lateral masses
What is significant about the structure of the axis (C2)?
The axis (C2) is significant in that it has the dens around which the atlas rotates. The atlas sits upon the superior articular surfaces. It has a large spinous process that can be felt in the back of the neck in the nuchal groove.
What is thoracic outlet syndrome and what problems can arise from this abnormality?
A group of disorders that occur when there is compression, injury, or irritation of the nerves and/or blood vessels in teh lower neck and upper chest area.
Causes:
extra rib in lower cervical region
fractured clavicle
extra muscle/scar tissue
poor posture of neck and shoulder regions
What are the identifying characteristics of the thoracic vertebrae?
The thoracic vertebrae look like giraffe heads:
body: larger, heart shaped, costal facets
spinous process: long and sharp, project inferiorly
vertebral foramen: circular
transverse process: facets for ribs (except T1-T12)
Superior and inferior articular processes: superior facets directed posteriorly, inferior facets directs anteriorly.
What are the identifying characteristics of the lumbar vertebrae?
Looks like bullwinkle’s head
body: massive, kidney shaped
spinous process: short & blunt, rectangular shaped, project posteriorly
vertebral foramen: triangular
transverse process: thin & tapered
superior & inferior articular processes: superior directed posteromedially, inferior directs anterolaterally or laterally.
movements allowed: flexion & extension, some lateral flexion, rotation prevented
What structures give the vertebral column its stability?
Articular discs between vertebral bodies
surrounding ligaments
What are the 5 important ligaments of the vertebral column?
- nuchal ligament
- supraspinous ligament
- interspinous ligament
- ligamentum flava
- intertransvers ligament
What does the intervertebral disc consist of?
The intervertebral disc consists of:
- anulus fibrosis
- nucleus pulposus
What and where is the nuchal ligament?
ligament at the back of the neck that is continuous wiht the supraspinous ligament.
What and where is the supraspinous ligament?
a cord like ligament along the vertebral column that connects together the apices of the spinous processes of the seventh cervical vertebra to the sacrum. This is strong in comparison to the interspinous ligament.
What and where is the interspinous ligament?
Ligament connecting the root to the apex of each spinous process. They meet the ligamentum flava in front and blend with the supraspinous ligament behind. These are weak in comparison to supraspinous ligament.
What and where is the ligamentum flava?
Ligament that links laminae of adjacent vertebra together. These ligaments prevent abrupt flexion of the spinal column and injury of intervertebral discs.
What and where are the intertransverse ligaments?
Ligaments that link the transverse processes of the spine.
What are the two craniovertebral joints?
- atlanto-occipital joints(c1- occipital bone)
- atlanto-axial joints. (atlas and axis)
What is the tectorial membrane?
Continuation of the posterior longitudinal ligament that joins the axis body to the foramen magnum.
What does the cruciate ligament consist of and what is its function?
Cruciate ligament includes:
- superior longitudinal band (weaker): reaches up to occipital bone.
- transverse ligament of atlas: creates collar around dens of atlas.
- inferior longitudinal band (weaker): reaches down to C2
How many articulations are seen in the atlanto-axial joint and what types of joints are they?
There are 3 articulations within the atlanto-axial joint
- 2 lateral atlanto-axial joints: inf facets of C1 and sup facets of C2 = synovial joints
- 1 median atlanto-axial joint: dens of C2 and anterior arch of the atlas = pivot joint
Where is the alar ligament and what is its function?
The alar ligament is found extending from the dens of axis to the lateral sections of the foramen magnum. This ligament prevents exccessive rotation of the atlas.
what are the 3 ligamentous structures that maintain the intervertebral joints?
- annulus fibrosis (fibrous outer layer of discs)
- anterior longitudinal ligament (broad): this is the only ligament that prevents hyperextension of the vertebral column.
- posterior longitudinal ligament (narrow)
In what segment of the vertebral column are invertebral discs the thickest and why?
Intervertebral discs are thickets in the cervical region and the thickness of IV discs is correlated with the range of motion.
what type of motion is extension of the back?
A motion similar to doing a back bend
What motion is flexion of the back?
bending over forward is flexion of the back
What is the function of the nucleus pulposus?
The nucleus pulposus acts to absorb shock to the vertebral column and contributes to flexibility of the vertebral column. Under tension and compression the nucleus pulposus deforms and acts as a semifluid fulcrum.
Where do herniationed discs tend to occur and in what direction?
Herniated discs tend to occur in the lumbar region and occurs in the posterior and lateral direction, because the posterior longitudinal ligament is not very broad.
What is a herniated disc?
herniated disc is when the nucleus pulposus pushes through the anulus fibrosis and sometimes puts pressure on the spinal cord causing pain.
What are the three types of impingements that can occur on the spinal cord?
- central stenosis
- foraminal stenosis
- herniated disc
What are causes of thoracic disc herniation?
- usually wear and tear and disc degeneration
- twisting of the midback
- scheuermann’s disease (extreme kyphosis)
What are some causes of lumbar herniated discs?
- frequent bending, twisting, lifting
- acute injury or fall in sitting position
What arteries supply blood to the cervical vertebral column?
- vertebral arteries
- cervical arteries
What arteries supply blood to the thoracic vertebral column?
- posterior intercostal arteries
What arteries supply blood to the lumbar vertebral column?
- subcostal arteries (not shown in pic)
- lumbar arteries
What arteries supply blood to the sacral vertebral column?
- iliolumbar arteries
- medial & lateral sacral arteries
What are the 4 venous plexi of the vertebral column?
- internal vertebral venous plexus
- external vertebral venous plexus
- basivertebral veins
- intervertebral veins
