TS Anatomy Flashcards
Unique features of thorax - in one typical vertebra (T2-T9) there will be 12 separate articulations for what structures?
- superior articular processes (2) for facet joints above
- inferior articular processes (2) for facets joints below
- superior demi-facets (2) for costovertebral joints
- inferior demi-facets (2) for costovertebral joints
- transverse process facet (2) for costotransverse joints
- intervertebral joints (2)
Relative stability of the TS compared to the LS & CS is due to:
- rib cage (increase stability of unit nearly 3x & greatly decrease mobility)
- attachment of rib head to intervertebral disc
- angulation of facets & decreased disk height
T/F: any movement occurring at any joint of each ring (costovertebral, costotransverse, sternocostal or facet joint) can potentially influence motions at the other joints within the ring or adjacent segments.
True
Why is the integrity of the thoracic ring important?
-it is critical to the stability of the thorax
Which other musculoskeletal dysfunctions can the thoracic spine contribute to?
- shoulder
- AC/SC
- neck
- lumbar
What are the functional regions of the thoracic spine?
- cervicothoracic junction (CT junction)
- middle thoracic spine
- thoracolumbar (TL) junction
What are the segments that make up the cervicothoracic (CT junction)?
-C7 through T3
What are the segments that make up the middle thoracic spine?
-T4 through T9
What are the segments that make up the thoracolumbar (TL) junction
-T10 through L1
Anatomy of the vertebromanubrial region (classified by Diane Lee)
-upper thorax, T1-2 + Rib 1-Rib 2 + manubrium
Anatomy of the vertebrosternal region (classified by Diane Lee)
-middle thorax, T3-T7 + Rib 3-Rib 7 + sternum
Anatomy of the vertebrochondral region (classified by Diane Lee)
-middle/lower thorax, T8-T10 + Rib 8 - Rib 10
Anatomy of the thoracolumbar region (classified by Diane Lee)
-lower thorax, T11-12 + Rib 11 - Rib 12
Anatomical orientation of the vertebral bodies and intervertebral discs in the thoracic spine?
-vertebral bodies & intervertebral discs are higher posteriorly than anteriorly
How does the anatomical orientation of the vertebral bodies and intervertebral discs affect the load on the vertebral body in the TS?
-since both structures are higher posteriorly than anteriorly, there is increased load ventrally on the vertebral body
How do the vertebral bodies in the TS compare to the vertebral bodies in the LS?
-TS vertebral bodies are more wedge-shaped
Which thoracic vertebrae are considered typical in reference to their morphology?
T2-T9
Which thoracic vertebrae are considered atypical in reference to their morphology?
T1, T10, T11, T12
Which structures form the costovertebral joint (CVJ)?
-formed by the articulation between the head of the rib, the intervertebral disc and the vertebral body at the same level and the level above
Anatomical variations in T1?
-two ovoid facets for articulation with Rib 1 with two small demi-facets on the inferior aspect of the body for articulation with Rib 2
Anatomical variations in T9 and T10?
- T9 has two demi-facets for articulation with rib 9 & often, there is a small articulation between the superior aspect of the head of the 10th rib & the inferior aspect of the vertebral body of T9.
- occasionally, the 10th rib will articulate only with T10
Anatomical variations in T11 and T12?
-rib 11 and rib 12 articulate only with the vertebral body at the same level
Disc height ratio comparison between TS, CS and LS?
TS = 1:5 CS = 2:5 LS = 1:3
Why is it typical to see central disc protrusions of the annular type and not nuclear?
-the nucleus in the TS is so small
Schmorl’s nodes
-herniation of disc substance through cartilaginous plate of disc into the body of the adjacent vertebra
Why does a patient complain of band of pain with damage to the outer annulus of the intervertebral disc?
-poly-segmental innervation (patient will complain of band of pain)
Why does a patient complain of thumbprint pain with damage to the inner annulus of the intervertebral disc?
-mono-segmental innervations (thumbprint pain)
How does the ALL differ in the TS compared with the CS & LS?
-the TS ALL is narrower but thicker relative to CS & LS
TS anterior compartment structures?
- vertebral bodies
- intervertebral discs
- ligaments (ALL)
What structures form the vertebral arches in the TS?
-the lamina & pedicles
Function of the vertebral arch?
-protects spinal cord
Where is the spinal canal smallest?
-middle thoracic segments (T4-T9)
What junctions have large spinal canals?
- cervico-thoracic junction
2. thoraco-lumbar junction
TS lamina
-when disc protrudes dorsally there is no chance for other structures to move out of the way. a very small protrusion of the disc can cause immediate dural irritation
TS pedicle
-located cranial, short & thick
T/F - it is common to have facet orientation asymmetry in the TS
true
Upper facet segments orientation:
-45-60 degrees from horizontal in the coronal plane
Middle facet segments orientation:
-50-60 degrees from the horizontal in the coronal plane (or 20 deg. in the transverse plane)
Lower facet segments orientation:
-inferior facets of T11 and T12 can resemble lumbar Z joint (in sagittal plane) changing by 90 degrees
Convex/concave rule for TS facet joints
-superior facets are slightly convex & inferior facets are slightly concave
Facet joints innervation for TS?
-medial branch of dorsal rams, supplied by axons from 1 to 2 adjacent root levels above, the same level & 1-2 levels below
Description of spinous processes?
-long (5-6 cm), slender & triangular shape
Function of spinous processes?
-increase inferior angulation
Location of transverse process in relation to spinous process for T1-T3?
-TP is directly lateral to the SP
Location of transverse process in relation to spinous process for T4-T9?
-TP is superior to the SP (as many as 3 fingers)
Location of transverse process in relation to spinous process for T10-T12?
-gradual transition of TP lateral to SP