What is the height pattern of the T12 vertebral body?
the posterior height is greater than the anterior height by one to two millimeters
What is the outline of the vertebral body of T12 on superior view?
kidney-shaped or reniform
What joints are identified at the vertebral body of T12?
- vertebral body to the longitudinal ligs. at the epiphyseal rims
- vertebral body to vertebral body via the intervertebral discs
- vertebral body to head of a rib (costocentral joint)
What joint classifications are identified at the vertebral body of T12?
- fibrous (amphiarthrosis) syndesmosis
- cartilaginous (amphiarthrosis) symphysis
- synovial plane (diarthrosis arthrodia)
What are the examples of fibrous (amphiarthrosis) syndesmosis joints at the T12 vertebral body?
superior and inferior epiphyseal rims to longitudinal ligaments
What are the examples of cartilaginous (amphiarthrosis) symphysis joints at the T12 vertebral body?
superior and inferior epiphyseal rims to intervertebral disc
What are the examples of synovial plane (diarthrosis arthrodia) joints at the T12 vertebral body?
superior costal facet to articular surface of the rib head (left and right)
How many synovial joints are formed at the vertebral body of T12?
2
How many symphysis joints are formed at the vertebral body of T12?
2
How many syndesmosis joints are formed at the vertebral body of T12?
typically 4 are identified (as many as 6 if the costocentral stellate/radiate lig. are included)
How many joints are typically formed at the vertebral body of T12?
typically 8 (10 if the costocentral stellate/radiate lig. are included)
How many costocentral joints are typically formed at the vertebral body of T12?
2
What synovial joint surfaces are present on the vertebral body of T12?
right and left superior costal facets
What is the relationship between the vertebral body surface and the rib head surface for the costocentral joint of T12?
the superior costal facet of T12 will joint with the articular surface of the head of the 12th rib
How does the superior costal facet compare with those of T11?
- it is larger
- below the superior epiphyseal rim
- it is completely circular
- often shared with the pedicle margin
What feature will provide assistance in maintaining the stability of the intervertebral foramen at T12?
costocentral joint or ribs
Which rib-vertebral body combination is typically present at the intervertebral foramen for the eleventh thoracic nerve?
the superior costal facet of T12 will joint with the articular surface of the head of the 12th rib at the margin of the intervertebral foramen
Which rib-vertebral body combination is typically present at the intervertebral foramen for the twelfth thoracic nerve?
the superior costal facet of T12 will joint with the articular surface of the head of the 12th rib above the intervertebral foramen
The costocentral stellate/radiate lig. will attach to what features?
- head of 12th rib
- vertebral bodies of T11 and T12
- intervertebral disc at the costocentral joint for the 12th rib
How many costocentral stellate/radiate lig. attach to the vertebral body of segments T1-T11?
four: 2 superior and 2 inferior
Which segment will be the last one to demonstrate a superior and an inferior costocentral stellate/radiate lig. attachment?
vertebral body of T11
How many costocentral stellate/radiate lig. attach to T12?
two: a right and left superior
Which lig. of the costocentral joint is absent for the 12th rib?
costocentral interarticular or intra-articular
Which muscles are attached to the vertebral body of T12?
- psoas major
- psoas minor
What is the position and direction of the pedicle from the vertebral body at T12?
the pedicle arises from the upper third of the vertebral body and projects posterior
What is present at the transverse process region of T12?
three tubercles of variable size
Which tubercle on T12 represents the transverse process?
lateral tubercle
Which tubercle on T12 represents the mammillary process of lumbars?
superior tubercle
Which tubercle on T12 represents the accessory process of the lumbars?
inferior tubercle
What is the location of the lateral tubercle?
it projects laterally from the pars interarticularis of T12
What is the location of the superior tubercle?
it projects superiorly over the superior articular facet from the pars interarticularis of T12
What is the location of the inferior tubercle?
it projects from the pars interarticularis of T12 in a plane that is inferior to the superior tubercle and medial to the lateral tubercle
Which is the smallest of the tubercles at the transverse process region of T12?
inferior tubercle
What joint surface of the typical thoracic transverse process is absent on T12?
transverse costal facet
What ligaments form the costotransverse joint of T12?
- superior costotransverse lig. from T11
- lumbocostal lig. from L1
What lig. is said to attach to the transverse process of T12?
intertransverse lig.
Which costotransverse lig. are attached at T12?
none
What is the joint classification associated with the intertransverse lig.?
fibrous (amphiarthrosis) syndesmosis
What muscles attach to the transverse process region of T12?
- longissimus thoracis
- semispinalis thoracis
- multifidis
- rotator longus
- rotator brevis
- intertransversarii
Which erector spinae muscle attaches to the transverse process region of T12?
longissimus
Which erector spinae muscles will not attach to the transverse process region of T12?
- spinalis
- iliocostalis
Which muscles attaching to the transverse process region of T12 are examples of the transversospinalis group?
- semispinalis thoracis
- multifidis
- rotator longus
- rotator brevis
Which rib-associated muscle is absent at the transverse process region of T12?
levator costarum
Which segment is the last to demonstrate a levator costarum brevis attachment?
T11
Which segment is the last to demonstrate a levator costarum longus attachment?
T10
What is the orientation of the superior articular facets of T12?
backward, upward, and lateral (BUL)
What is the orientation of the inferior articular facets of T12?
forward, downward, and lateral (FoLD)
What is the curvature of the superior articular facets of T12?
slightly concave
What is the curvature of the inferior articular facets of T12?
slightly convex
How may synovial joints are typically present at T12?
6
Identify the synovial joint surfaces typically present on T12.
- two superior costal facets
- two superior articular facets
- two inferior articular facets
How many synovial joint surfaces for ribs are typically present on T12?
2
Identify the synovial joint surfaces for ribs that are typically present on T12.
two superior costal facets
Which rib-related facets are absent on T12?
- inferior costal demi-facets
- transverse costal facets
What is the orientation of the spinous process of T12?
posterior and horizontal
What is the length of the spinous process of T12?
it is similar to the spinous process of T11
What is the generic appearance of the spinous process of T12?
lumbar-like, similar in length to T11
What ligaments attach to the spinous process of T12?
- interspinous lig.
- supraspinous lig.
What joint classification is associated with lig. attaching to the T12 spinous process?
fibrous (amphiarthrosis) syndesmosis
What muscles attach to the spinous process of T12?
- trapezius
- latissimus dorsi
- serratus posterior inferior
- iliocostalis lumborum
- spinalis thoracis
- multifidis
- rotator longus
- rotator brevis
- interspinalis
Which erector spinae muscles will attach to the spinous process of T12?
- spinalis
- iliocostalis
Which erector spinae muscles will not attach to the spinous process of T12?
longissimus
Which transversospinalis muscles attach to the spinous process of T12?
- multifidis
- rotators
Which of the muscles of the 5 layers of the true back are present at the T12 spinous process?
- trapezius
- latissimus dorsi
- serratus posterior inferior
- iliocostalis lumborum
- spinalis thoracis
- multifidis
- rotator longus
- rotator brevis
Which of the erector spinae muscle groups is absent at the T12 spinous process?
longissimus
Which of the transversospinalis muscle groups is absent at the T12 spinous process?
semispinalis
Which of the muscle layers of the true back are represented at the T12 spinous process?
layers 1, 3, 4, and 5
Which of the muscle layers of the true back is absent at the T12 spinous process?
layer 2
Which muscles attaching to the spinous process of T12 are not included in any muscle layer of the true back?
interspinalis
What joint classifications are present at T12?
- fibrous (amphiarthrosis) syndesmosis
- cartilaginous (amphiarthrosis) symphysis
- synovial plane (diarthrosis arthrodia)
At what parts of T12 will the fibrous (amphiarthrosis) syndesmosis joint be observed?
- vertebral body
- lamina
- transverse process
- spinous process
At what part of T12 will the cartilaginous (amphiarthrosis) symphysis joint be observed?
vertebral body
At what parts of T12 will the synovial plane (diarthrosis arthrodia) joint be observed?
- vertebral body
- articular process