Week 5 - Spinal cord Flashcards
How many vertebrae are in the cervical region?
7
How many V in the thoracic region?
12
How many V in the abdomen/lumbar?
5
How many V are in the sacrum?
5 - fused
How many vertebrae in the coccyx?
4 - fused
What are typical vertebrae of a region?
Those with characteristic features.
Some are atypical
When is the spine kyphotic?
When a foetus - this is the primary curveature
When is there secondary curvature of the spine? What does it look like
After birth
Neck and lumbar regions become convex forwards
What are three types of spinal curvature abnormalities?
Lordosis - excessive forward convexity
Kyphosis - excessive forward concavity
Scoliosis - lateral curvature
Why does the spine change from primary to secondary in curvature?
Because of muscular activity
What forms the canal for the spinal cord in the vertebrae
The neural arch completing a circle with the weight bearing body
What are the processes of the vertebrae?
- Spinous process
- Transverse R + L process
What is a facet?
Part of the process (a flat area) is covered by hyaline cartilage
What is an articular process on joint?
This bears the facet
What’s the most important thing a thoracic vertebrae does?
Forms jont with the rib
Where is the rib attachment?
There are two on the body of the vertebrae, one on the transverse prpcess
What is a characteristic of thoracic vertebrae?
- They have three attachments
- Backwards pointing transverse process
Describe the canal of the thoracic vertebrae?
Small and almost circular, has the smaller diameter
Describe the spinous process of thoracic V
Long and pointed with a slope
Describe the cervical V
Broad and flat
- Has a foramen (foramen transversarium)
- Has two tubercles
What is unique about the cervical V?
Spine isn’t really pointed, it’s split into two = bifid spine
Describe the lips of the cervical V
These ridges are anterior and posterior, unmistakeable
Describe the canal of the cervocal V
Canal is large and triangular
Describe the articular facets of the cervical V
Large and move backwards
Describe the transverse processes of the lumbar V
Thin, bladelike and absolutely transverse
Describe the cervicalspinous process
Thick and when looked at from the side, roughy quadrangular
What is distinctly curved in the lumbar V?
The articular processes and the facets
Which vertebrae are some of the largest
Lumbar - has to bear more weight
Where are foramina in the sacrum?
At the front and the back - seperate ones for ventral and dorsal rami
Which are the atypical vertebrae?
C1, C2, C7, Upper and lower thoracic, L5
Describe C1
This is ‘Atlas’. Articular facets are long and hollowed out.
Completely missing part of the V body - looks like a large ring
Describe C2
This is ‘axis’
Sitting on top of the body is the part of the body missing from C1, sticks out like a tooth (dens)
What passes through foramen transversarium?
An artery that goes straight up to the skull (vertebral artery)
What does flexion and extension do on C1
Head slides over the articular facets of C1
What moves when shake your head?
head of 1st vertebrae moves over second vertebrae
Describe C7
Has a long, undivided spinous process (vertebrae prominens)
Describe L5
Has much thicker transverse processes than the rest of the lumbar Vs. This is for the strong iliolumbar ligament
What is the intervertebral disc made of?
White fibrocartilage
Thinner posteriorly
Where are intervertebral symphysis?
Between bodies of vertebrae.
Describe the WFC dis of the V
The fibrous ring (annulus fibrous) is made up of an outer part, which is more fibrous and merges with fibrous tissue surrounding it + the inner part, which has more chondrocytes
Where would you find nucleus pulposus?
This is the inner jelly-like core of the intervertebral WFC disc. It’s the remains of the notocord
Where does the degree of mobility of the vertebral column come from?
WFC - slightly deformable
Adjacent vertebrae - minimal movement
Adds up
Describe facet/Z joints & their movements
Made up of articular facets, they’re plane synovial and have very little movement –> mostly for adjustments
What are the ligaments that run along V bodies?
- In front of the body is the anterior longitudinal ligament
- On posterior surface of the body is the posterior longitudinal ligament
What are the ligaments between two neighbouring process spines?
Interspinous ligaments
Where does supraspinous ligament sit?
Connects the tips of 3-4 spinous processes of the vertebrae
What connects laminae of neighbouring vertebrae?
Thin ligaments with lots of elastic fibres –> yellow colour
= ligamentum/ligamenta flava
Are the posterior vertebral muscles epaxial or hypaxial?
Epaxial, supplied by dorsal rami
What are the superficial posterior group of muscles of the spinal column?
The erector spinae group
What is the deeper group of the posterior side of the vertebral column?
Transversospinales group
What are suboccipital muscles used for?
Movements of the head
Occipital bone, atlas and axis
Which anterior long cylindrical muscle can flex the vertebral column?
Psoas major muscle
What are the movements of the spine?
Flexion/extension
Lateral flexion: right or left
Rotation
What is rotation of V column limited by?
Spinal fibres in the disc
Which areas of the spine are best at rotating?
Thoracic column, then cervical
What increases spinal range of motion?
Flexion assisted by tip joint, but tight hamstrings can limit
Rotation is assisted by pelvic and head
What is the intervertebral foramen completed by?
Notch on lower of upper V, notch on upper side of lower V
What contributes cartilage to the intervertebral foramen?
The intervertebral disk on the medial side, and the facet joint on the lateral side
What makes up the intervertebral foramen?
Vertebral body
Intervertebral disc
Two notches
Facet joint
What happens when the spinal nerve exits the IV foramen?
The dorsal ramus winds around articular process
What forms each vertebrae developmentally?
Parts of neighbouring sclerotomes
How do sclerotomes contribute to vertebrae?
Each sclerotome contributes to two vertebrae
What forms IV disc?
A part of sclerotome, between the two bits that contribute to different Vs –> centre of every segment
How are the discs and nerves aligned to each other during development?
In each segment, the nerve is central - aligned to the disk
This means that if the nerve is central to a segment, the disk is also central
Where are the primary centres of ossification in vertebral?
There’s a single centrum that’s contributed to by two centres merging to one,and there are two in the neural arch
Where are the secondary centres of ossification in the V?
At the annular epiphysis - around the margin of the body
AND
At tips of processes
What makes up the body of the V?
The centrum + annular epiphysis + ‘root’ of neural arch
Which vertebral are capable of growing a rib?
Every single one
WHen element of transverse process is able to grow a rib
The costal element, NOT the transverse element
What are the two elements of the transverse processes?
Cost element
Transverse element
Where are developmental abnormalities normally found in the spine?
Post-thoracic aka L+S, 4+6 or 6+4
What is hemivertebra?
Abnormal curvature
What is spina bifida?
“split spine”. Vertebral defect can be seen by imaging, accompanied by spinal cord/meningeal anomalies
What is the cervical rib defect?
When the costal element enlarges, usually in C7. This isn’t always bone (can be cartilage), and usually joins first rib, contributing to thoracic outlet syndrome
What is paraspinal spasm?
When one side of the spinal column are hard
What are some causes of back pain?
Bone - esp periosteum
Small tears or prolapse in the WFC disc
Ligaments in the facet joints
What’s the link between the spine and cancer?
Vertebral column is a frequent site for malignant metastases in bone
Why are vertebral bodies prone to fracture and OP?
It’s a thin, compact bone with a cancellous interior
What is a prolapse?
Protrusion of nucleus pulposus
