Vertebral Column Flashcards
What is the number of vertebrae in a typical adolescent?
33 segments
What is the number of vertebrae in a typical adult?
26 segments
What constitutes the spine?
The 24 presacral segments; the cervical, thoracic and lumbar vertebrae
Which mammals have more than seven cervical vertebrae?
The ant bear and three-toed sloth
Which mammals have less than seven cervical vertebrae?
The manatee and two-toed sloth
What does the term cervical refer to?
The region of the neck
What does the term thoracic refer to?
Breast plate or chest; it referred to the armor bearing region of the torso
What other term is often used to identify the vertebral segments of the chest?
The dorsal segments the dorsals
What does the term lumbar refer to?
The loin; the region between the rib and hip
What does the term sacrum refer to?
The holy bone of holy region
What does the term coccyx refer to?
A cuckoo birds’ bill or cuckoo birds’ beak
What is the length of a typical male spinal column?
About 70 cm or 28 in
What is the length of a typical female spinal column?
About 60 cm or 25 in
What is the length difference between a typical male and typical female spinal column?
About 3 inches
What is the length of the male thoracic region?
About 12 cm or 5 in
What is the length of the male lumbar region?
About 18 cm or 7 in
What is the length of the male sacrum?
About 12 cm or 5 in
Based on the numbers for individual regions of the vertebral column, what is the length of the male spine?
About 58 cm or 23 in
How does the vertebral column participate in skeletal formation?
Ribs are formed from the costal process of the embryonic vertebral template
What levels of the vertebral column specifically accommodate weight-bearing transfer?
S1-S3 at the auricular surface
What is specifically responsible for shape and position of the human frame?
Comparative anterior vs. posterior height of the vertebral body and comparative anterior vs. posterior height of the intervertebral disc
What organ(s) is (are) specifically associated with the horizontal axis of the skull?
The eye and the vestibular apparatus of the inner ear
Invagination of ectoderm along the primitive streak gives rise to what embryonic structure?
Notochord
What is the name given to the mesoderm that will give rise to the vertebral column?
Paraxial mesoderm
Name the areas of cellular differentiation formed within the somite.
Sclerotome, myotome, and dermatome
What are the names of the successive vertebral columns formed during development?
Membranous, cartilaginous, skeletal or osseous
Migration of a somite pair to surround the notochord forms what developmental feature?
The perichordal blastema
The perichordal blastema gives rise to what processes?
Neural processes and costal processes
What is the name of the artery located between adjacent perichordal blastemae?
Intersegmental artery
What forms between the sclerotomites of a perichordal blastema?
The intrasclerotomal fissue (fissue of von Ebner)
The intersclerotomal fissure (fissure von Ebner) gives rise to what developmental feature?
The perichordal disc
The union of a dense caudal sclerotomite and a loose cranial sclerotomite from adjacent perichordal blastemae gives rise to what feature?
The vertebral blastema
What vessel will be identified adjacent to the vertebral blastema?
The segmental artery
When will cartilage first form in the membranous vertebral blastema?
Beginning in the 6th embryonic week
What is the name given to the replacement of mesoderm by cartilage?
Chondrification
How many centers of chrondrification typically appear in the vertebral blastema?
Six… 2 for the centrum, 2 for neural arches, 2 for each transverse process
What is the earliest time that centers of ossification appear in the cartilaginous vertebra?
During the 7th embryonic week
What is the name given to centers of ossification based on time of appearance?
Primary centers appear in utero, secondary centers appear after birth
What is the ratio of primary to secondary centers of ossification for a typical vertebra?
3 primary centers: 5 secondary centers
What are the names of the primary centers of ossification for a typical vertebra?
Centrum centers and neural arch centers
What are the names/locations of the five secondary centers of ossification for a typical vertebra?
Tip of the transverse process, tip of the spinous process, epiphyseal plate centers
What is the range of appearance for secondary centers of ossification of a typical vertebra?
During puberty, typically ages 11-16 years old
What is the general shape of the vertebral body at each region of the spine?
Cervical- rectangular
Thoracic- triangular
Lumbar- reniform
What is the name given to the compact bone at the superior and inferior surfaces of the vertebral body?
Superior epiphyseal rim, inferior epiphyseal rim
What is the name given to the intermediate part of the vertebral arch where the transverse process and articular processes attach?
The lamina- pedicle junction
What is the generic orientation of the pedicle at each region of the spine?
Cervical- posterolateral
Thoracic- posterior, slight lateral
Lumbar- posterior
What ligament will attach to the lamina?
The ligamentum flavum
What is the name given to abnormal bone at the attachment site of the ligamentum flavum?
Para-articular process
What classification of bone will para-articular processes represent?
Accessory bone
What is the name given to the overlap of laminae seen on X-ray?
Shingling
What is the name given to the lamina- pedicle junction at each region of the spine?
Cervical- articular pillar
Thoracic and lumbar- pars interarticularis
What is the name given to the junction of the vertebral arch- spinous process on lateral X-ray?
The spinolaminar junction
What is the generic orientation of the transverse process or transverse apophysis at each region of the spine?
Cervical- anterolateral
Thoracic- posterolateral
Lumbar- lateral
All non-rib-bearing vertebra of the spine retain what equivalent feature?
The costal element
What will cause the transverse process/transverse apophysis to alter its initial direction in the cervical region?
Cervical spinal nerves are pulled forward to form the cervical and brachial nerve plexuses thus remodeling the transverse process to accommodate their new position
What will cause the transverse process/transverse apophysis to alter its initial direction in the thoracic region?
The growth of the lungs remodel the shape of the ribs which in turn push the transverse processes backward
What is the name given to the joint formed between articular facets of a vertebral couple?
The zygapophysis
What will form the posterior boundary of a typical intervertebral foramen?
The inferior articular process/post-zygapophysis, the superior articular process/pre-zygapophysis, the capsular ligament, and the ligamentum flavum
What will form the superior boundary of a typical intervertebral foramen?
The inferior vertebral notch or inferior vertebral incisure
What will form the inferior boundary of a typical intervertebral foramen?
The superior vertebral notch or superior vertebral incisure
What will form the anterior boundary of a typical intervertebral foramen?
The vertebral body of the segment above, the vertebral body of the segment below, the intervertebral disc, and the posterior longitudinal ligament
What is the method of calculating the angle of the spinous process/spinous apophysis?
Calculate the angle formed between the undersurface of the spinous process/spinous apophysis and the horizontal plane
What is the name given to the normal overlap of spinous processes or spinous apophyses as seen on X-ray?
Imbrication
What is the orientation of the spinous process/spinous apophysis at each region of the spine?
Cervical- slight angle inferiorly
Thoracic- noticeable angle inferiorly
Lumbar- no inferior angle
What is the typical shape/ outline of the vertebral foramen at each region of the spinal column/vertebral column?
Cervical- triangular
Thoracic- oval
Lumbar- triangular
Sacrum- triangular
At what vertebral level will the spinal cord typically terminate?
L1
At what vertebral level will the dural sac typically terminate?
S2
What are the segmental arteries of the cervical spine?
The vertebral artery, ascending cervical artery and deep cervical artery
What are the segmental arteries of the thoracic spine?
The deep cervical artery, superior (highest) intercostal artery, posterior intercostal artery and subcostal artery
What are the segmental arteries of the fifth lumbar vertebra?
The iliolumbar artery, lateral sacral artery and median (middle) sacral artery
What segmental levels are supplied by the deep cervical artery?
C1-C6
What segmental levels are supplied by the ascending cervical artery?
C1-C6
What segmental levels are supplied by the deep cervical artery?
C7-T1
What segmental levels are supplied by the superior (highest) intercostal artery?
T1, T2
What segmental levels are supplied by the posterior intercostal artery?
T3-T11
What segmental level(s) is/are supplied by the subcostal artery?
T12
What segmental levels are supplied by the lumbar arteries?
L1-L4
What segmental levels are supplied by the median (middle) sacral artery?
L5, S1-S5 and coccyx
What segmental levels are supplied by the iliolumbar artery?
L5, S1-S5 and coccyx
Which vertebra has the greatest number of segmental arteries associated with it?
L5
What are the segmental arteries for L5?
iliolumbar artery, median (middle) sacral artery, and lateral sacral artery
What branch of the segmental artery supplies the vertebra and the paravertebral region?
Dorsospinal artery
Which artery is primarily observed in the distal part of the intervertebral foramen?
Spinal artery
Which branch of the dorsospinal artery will penetrate the meninges to enter the subarachnoid space?
Spinal artery
What are the branches of the spinal artery?
Osseous arteries, anterior spinal canal artery, posterior spinal canal artery, anterior medullary feeder artery, posterior medullary feeder artery, anterior radicular artery, posterior radicular artery
Which branches of the spinal artery supply the contents of the epidural space?
Osseous arteries, anterior spinal canal artery, posterior spinal canal artery
What arteries are observed in the epidural space near the posterior longitudinal ligament?
Anterior spinal canal artery and plexus
What arteries are observed in the epidural space near the ligamentum flavum?
Posterior spinal canal artery and plexus
Which branches of the spinal artery supply the contents of the subarachnoid space?
Anterior radicular artery, posterior radicular artery, anterior medullary feeder artery, posterior medullary feeder artery
Which vessel will supply the ventral/anterior nerve rootlet and nerve root?
Anterior radicular artery
Which vessel will supply the dorsal/posterior nerve rootlets, nerve root and nerve root ganglion?
Posterior radicular artery
What is the location and number of medullary feeder arteries present in the adult?
9 anterior and 12 posterior medullary feeder arteries
What is the name given to the artery that lies in front of the spinal cord along its length?
Anterior spinal artery
The anterior spinal artery is a branch of which artery?
The vertebral artery
Is the anterior spinal artery a single, continuous artery along the spinal cord?
No
As the anterior spinal artery continues along the spinal cord, which arteries unite along its length to give the appearance of a single continuous vessel?
Anterior medullary feeder arteries
The posterior spinal artery is a branch of which artery?
The posterior inferior cerebellar artery
What is the position of the posterior spinal artery relative to the spinal cord?
It lies in the posterolateral sulcus along the spinal cord
Is the posterior spinal artery a single, continuous artery along the spinal cord?
No
As the posterior spinal artery continues along the spinal cord, which arteries unite along its length to give the appearance of single continuous vessel?
Posterior medullary feeder arteries
What forms the arterial vasa corona above C3?
Right and left anterior spinal arteries, right and left posterior spinal arteries, and 4 communicating arteries
What forms the arterial vasa corona below C6?
A median anterior spinal artery, right and left posterior spinal arteries, and 3 communicating arteries
What is the generic name given to arteries that penetrate the spinal cord?
Intramedullary arteries
What are the intramedullary branches of the arterial vasa corona?
Pial perforating arteries, central/ventral/sulcal perforating arteries
What arterial vasa corona branches supply gray matter and most of the spinal cord?
Ventral/central/sulcal perforating arteries
What intramedullary branches supply about one third of the spinal cord?
Pial perforating arteries
What is the source for pial perforating arteries?
The pial plexus
What is the primary artery supplementing the arterial vasa corona?
Anterior medullary feeders and posterior medullary feeders
What vessels drain the spinal cord?
Pial veins
What will pial veins drain into?
Venous vasa corona
Which vessels form the venous vasa corona?
Right and left anterior longitudinal veins, right and left posterior longitudinal veins and 4 communicating veins
What vessel will drain the venous vasa corona?
Anterior medullary veins, posterior medullary veins
What vessel will drain the dorsal/posterior nerve root ganglion?
Posterior radicular veins
What veins are observed in the epidural space near the posterior longitudinal ligament?
Anterior internal vertebral venous plexus, basivertebral vein
What veins are observed in the epidural space near the ligamentum flavum?
Posterior internal vertebral venous plexus
What venous vessels are identified in the intervertebral foramen?
Intervertebral veins
Identify the meninges of the spinal cord (spinal medulla or medulla spinalis).
Dura mater, arachnoid mater, pia mater
What is the name given to fluid within the epidural space?
Interstitial fluid
Which meningeal space is now thought to be a potential space, not an actual space?
Subdural space- between the dura mater and arachnoid mater
Which of the contents of the epidural space are more likely located near or around the posterior longitudinal ligament?
Anterior spinal canal artery and plexus
Anterior internal vertebral venous plexus
Basivertebral vein
Recurrent meningeal/sinu-vertebral/sinus vertebral nerve
Hofmann/anterior dural/meningovertebral ligaments
What is the name given to the fluid present within the subdural space?
Serous fluid
What is the name given to the fluid with the subarachnoid space?
Cerebrospinal fluid
What is the name given to the lateral extension of pia mater along the spinal cord?
Dentate (denticulate) ligament
What is the unique feature of veins along the spinal cord?
They lack the bicuspid valve of typical veins
In horizontal view, what direction of the spinal cord tends to be largest?
Transverse
What are the spinal cord enlargement locations and the name given to each?
C3-T1, the cervical enlargement; T9-T12, the lumbar (lumbosacral) enlargement
Where is the greatest transverse diameter of the spinal cord?
C6
What is a generic cord level of origin- vertebral level combination for the lumbar (lumbosacral) enlargement?
L1, L2 cord levels in T9
L3, L4 cord levels in T10 vertebra
L5, S1 cord levels in T11 vertebra
S2, S3 cord levels in T12 vertebra
What is the caudal end of the spinal cord called?
Conus medullaris
What spinal nerves originate from the conus medullaris?
Typically S4, S5, and Co1
In which vertebral foramen will the conus medullaris typically be observed?
L1
What is the name given to the roots below L1?
Cauda equina
What is the continuation of pia mater below the conus medullaris called?
Filum terminale internum
What is the location and name given to the area where all meninges first converge at the caudal part of the vertebral column?
Typically S2, the dural cul de sac
Neural tissue has been identified in what part of the filum terminale?
Proximal part of the filum terminale internum
What is the fate of the neural tissue identified along the filum terminale internum?
It joins peripheral nerve roots of spinal nerves as high as L3 and as low as S4
What does the neural tissue accociated with the filum terminale externum appear to innervate?
Lower limbs and external anal sphincter
The last arterial vasa corona creates what feature on angiogram?
Cruciate anastomosis
What is the name given to the condensation of meninges below S2?
Filum terminale externum
What is the name given to the caudal attachment of the meninges?
Coccygeal medullary vestige
What is the name given to the condition in which the conus medullaris is located below L1 and the filum terminale is thickened?
Tethered cord syndrome
What is the relationship between scoliosis and tethered cord syndrome?
It is suggested that the column will change normal curvatures to mitigate damage to the spinal cord
What is the relationship between spinal nerve number, rib number, and vertebral number in a thoracic intervertebral foramen?
The spinal nerve number relates to the upper segment number in the vertebral couple
The rib number relates to the lower segment number in the vertebral couple
i.e. T3 nerve exits the intervertebral foramen formed by T3/T4 and rib 4 joints with this vertebral couple
