How many vertebrae are there and how are they organised?
33 in total
What are the structures labelled 1-7?
1. Vertebral body
2. Spinous process
3. Transverse process
5. Foramen/spinal canal
7. Superior facet
What kind of joints are facet joints?
What is the angle of the transverse processes at the cervical, thoracic and lumbar levels?
45, 60 and 90 degrees respectively
What do the transverse foramen in the cervical spine transmit?
Vertebral artery, vein and nerve fibres
Is there much movement in the thoracic spine?
No, due to attachment of ribs
Where is there greatest risk of injury to the spine and why?
Cervico-thoracic and thoraco-lumbar junctions
Junctions between fixed and mobile segments
Where is the risk of rupture to the vertebral disc highest?
Posterior annulus fibrosis - this is where it's thin
Which ligaments run along the surface and length of the vertebral column?
Anterior longitudinal ligament
Posterior longitudinal ligament
Which structure links the vertebral laminae?
Which structures link the spinous processes of the vertebrae and what strength are they?
Interspinous ligaments - between processes, relatively weak
Surpaspinous ligament - along the posterior aspect of the spinous processes, tough
What is the three column theory of Denis?
Assessment of stability of spinal injury
1 Column injured: stable
(OP wedge #)
2 columns injured: may be unstable
3 columns injured: unstable
What are the superficial/extrinsic muscles of the spine?
Rhomboid minor & major
What is the function of the superficial/extrinsic muscles of the spine?
Movement of shoulder and upper limb
Which muscle is being indicated here, and what is its function and innervation?
Elevates and depresses scapula, retracts scapula
Spinal accessory nerve (CN XI)
Which muscle is being indicated here and what is its function and innervation?
Adducts, extends and internally rotates the humerus
C6, 7, 8
Which group of muscles are being indicated here and what are their names?
Laterally - iliocostalis
In between - longisimus thoracis
Medially - spinalis thoracis
What is the origin and insertion of the erector spinae muscles?
Occiput of the skull
Inserts on the pelvis
What is the innervation of the erector spinae muscles?
Posterior rami of the spinal nerves
Where does the spinal cord exit the skull?
Where does the spinal cord terminate?
At the cauda equina, level L2
What is a myotome?
Muscles controlled by the motor element of the nerve root from a specific level
What is a dermatome?
Skin sensation supplied by the sensory element of the nerve root from a specific level
What are the parts of the spinal cord labelled 1-4?
1. Grey matter
2. White matter
3. Posterior horn
4. Anterior horn
What is contained within the white matter of the spinal cord?
The ascending sensory tracts
The descending motor tracts
What is significant about the path of the crossed pyramidal or lateral cerebrospinal tract?
(This is a descending motor tract)
Crosses over in the medulla
Descends in the spinal cord on the contralateral side
What is significant about the path of the uncrossed pyramidal or anterior cerebrospinal tract?
Descend the spine on the ipsilateral side of the cord
Crosses (decussates) at the same level it exits the cord so exits from the contralateral side
What is significant about the path of the posterior & anterior spinocerebellar tracts and what do these nerves carry?
Ascend the spine on the ipsilateral side of the cord
Enter the cerebellum
Carry information relating to proprioception
What is significant about the path of the lateral and anterior spinothelamic tracts and what do they carry?
Enter then ascend the spine on the ipsilateral side of the cord for a couple of levels
Then cross and ascend the spine on the contralateral side of the cord
Enter the thalamus
Carry information relating to pain & temperature
Which ascending tracts carry fine touch and proprioception to the brain?
Fasciculus gracilis of Goll
Fasciculus cuneatus of Burdach
Which are the descending tracts which cross over and descend on the contralateral side of the brain?
Crossed pyramidal or lateral cerebrospinal tract
Which are the ascending tracts which initially ascend on the ipsilateral side of the cord but cross over to contralateral side to reach the brain?
Lateral and anterior spinothelamic tracts
What happens in the grey matter to ascending and descending tracts?
The descending tracts enter the anterior horn of the grey matter and are transmitted via the ventral root to the nerve root then the muscle of action
Sensation is transmitted via the spinal nerve root to the dorsal root and into the posterior horn of the grey matter and via the ascending sensory tracts enter the brain
Which roots of the spinal cord join to become the nerve root?
Ventral and dorsal roots
Through which foramen does the spinal nerve exit the spinal column?
What structure forms the intervertebral notch?
The pedicle of the vertebrae has a notch above and below
When the vertebrae are stacked, the two notches form a hole
When the nerve travels through the intervertebral foramen, what is it as risk of?
Injury from facet joint osteophyte formation, disc prolapse or foraminal stenosis
What is the cauda equina?
A bundle of spinal nerves and nerve roots
What nerves are contained within the cauda equina?
L2 – L5
S1 – S5
What is Batson's venous plexus?
A network of valveless veins
Connect the deep pelvic veins and thoracic veins (draining the inferior end of the urinary bladder, breast and prostate) to the internal vertebral venous plexuses