Unit 2 - VI. Regions of the Vertebral Column: Thoracic or Dorsal Region Flashcards
Which thoracic segments are considered the typical thoracics?
T2-T8 segments
Which thoracic segments are considered the atypical thoracics?
T1, T9-T12
What features will allow discrimination between T2-T4 and T5-T8 segmental groups?
the vertebral body, transverse process, articular process and spinous process
What is the outline of the vertebral body of a typical thoracic from superior view?
triangular
On cranial view, what is the outline of the vertebral body for the T2-T4 group?
the vertebral body will have bilaterally convex sides
On cranial view, what is the outline of the vertebral body for the T5-T8 group?
the left side of the vertebral body will be flattened, the right side convex
What is the appearance of the vertebral body from the anterior view for T2-T4?
both sides will appear to be scalloped (indented) between the epiphyseal rims
What is the appearance of the vertebral body from the anterior view for T5-T8?
the left side will appear to be less scalloped (indented) between the epiphyseal rims compared to the right side
What is the cause for the flattening of the left side of the vertebral body on T5-T8?
The descending thoracic aorta will come to lie on the left side of the vertebral body in this region and prevent the epiphyseal plate cartilage from deforming as much as on the right side. When the epiphyseal plates ossify, the epiphyseal rim will not be pushed out as far on the left so that side of the vertebral body appears to be less scalloped.
What is the name given to the left side appearance of the vertebral body of T5-T8?
the aortic impression
What is the aortic impression?
the flattening of the superior and inferior epiphyseal rims on the left side of the vertebral body of T5-T8 which gives the vertebral body a less scalloped or less indented appearance on that side
What part of the vertebral body is most influenced by the aorta at T5-T8?
the left side superior and inferior epiphyseal rims
What is the height pattern of the typical thoracic vertebral body?
the posterior height is greater than the anterior height by one to two millimeters
What is the height pattern of intervertebral discs in the typical thoracic region?
the intervertebral discs are rather planar or flat with no apparent height difference between anterior and posterior heights
What is the principal cause of the posterior curve of the thoracic spine?
the vertebral body height differences
In terms of the anterior-posterior curves of the vertebral column, what direction will the thoracic spine face?
posterior
What is another way of naming a posterior curve pattern?
a kyphotic curve
What joints are identified at the vertebral body of a typical thoracic?
- vertebral body to anterior longitudinal ligament at the epiphyseal rims
- vertebral body to posterior longitudinal ligament at the epiphyseal rims
- vertebral body to vertebral body via the intervertebral discs
- vertebral body to capitulum of a rib (costocentral joint)
What joint classifications are identified at the vertebral body of a typical thoracic?
fibrous (amphiarthrosis) syndesmosis, cartilaginous (amphiarthrosis) symphysis and synovial plane (diarthrosis arthrodia)
What are the examples of fibrous (amphiarthrosis) syndesmosis joints at the vertebral body of a typical thoracic?
- superior and inferior epiphyseal rim to anterior longitudinal ligament
- superior and inferior epiphyseal rim to posterior longitudinal ligament
What are the examples of cartilaginous (amphiarthrosis) symphysis joints at the vertebral body of a typical thoracic?
- superior epiphyseal rim to intervertebral disc
- inferior epiphyseal rim to intervertebral disc
What are the examples of synovial plane (diarthrosis arthrodia) joints at the vertebral body of a typical thoracic?
- right and left superior costal demi-facet to inferior articular surface of the rib head
- right and left inferior costal demi-facet to superior articular surface of the rib head
How many synovial joints are formed at the vertebral body of a typical thoracic?
four
How many symphysis joints are formed with the vertebral body of a typical thoracic?
two
How many syndesmosis joints are formed at the vertebral body of a typical thoracic?
typically four are identified (as many as eight if the costocentral stellate/radiate ligaments are included)
How many joints are formed at the ventral body of a typical thoracic?
typically ten (fourteen if the costocentral stellate/radiate ligaments are included)
What is the name given to the joint formed between the vertebral body and rib?
costocentral joint