6- Thoracic Spine Flashcards
How does the thoracic spine compare to the rest of the spine? why? What does it contribute?
it is overall stiffer and less mobile because of the ribcage
It adds significantly to the mechanical stability
What is thoracic kyphosis a result of?
lesser anterior height of vertebral body and wedge shape of discs
What is average thoracic kyphosis?
20-40 degrees
Where is the apex of the thoracic kyphosis curve?
T7-8
Which thoracic vertebrae are typical?
T2-T10 (11 and 12 are atypical)
What are the thoracic IVDs like?
narrower and flatter
thoracic IVDs contribute approximately ______ of the length of the thoracic column?
1/6th
How are the nerve roots situated in the thoracic spine? Is this good or bad?
situated behind inferior-posterior aspect of upper VB rather than the disk
Good- decreases risk of root compression
What is significant about the thoracic spinal canal?
relatively narrow (mainly T4-9)
Where is the tension point in the thoracic spine?
T6
How are the thoracic SPs positioned?
first and last 3 are almost horizontal… mid-thorax are long and steeply inclined
Compressive Loading:
T1 endures ______% body weight
T8 endures ______%
T12 endures ______%
T1- 9%
T8- 33%
T12- 47%
Explain the “Thoracic Rule of Threes”
T1-3: SPs level with their own VB
T4-6: SPs are level with IVD
T7-9: SPs in line with lower TPs
T10-12: by T12 in line with TPs
Superior articular facets of the thoracic vertebrae face _______.
Posterior
Lateral
Superior
Inferior articular facets of the thoracic spine face ______.
Anterior
Medial
Inferior
Angle of the facets in the thoracic spine is _____ degrees away from the frontal plane.
20-30
What is different about T12?
transitional vertebra ( superior facets are in the frontal plane, inferior are in the saggital )
Which ribs are true ribs? What makes them true?
1-7 (cartilage attaches directly to sternum)
Which ribs are false ribs? What makes them false?
8-12 (distal attachment is to the costochondral cartilage of the superior neighbor)
Which ribs are typical? What makes them typical?
3-9 are typical
They have a posterior end with a head, neck, and tubercle. the head has 2 articular facets a superior costal facet, an an inferior costal facet
Which ribs are atypical? Why?
1, 2, 10, 11, 12 are atypical
They only articulate with their own vertebrae via one full facet
Which ligaments add strength to the weak anterior capsule of the costotransverse ligament?
Medial, Lateral, and Superior costotransverse ligaments
What type of joint is between the first rib and sternum?
synchondrosis
The remainder of the sternocostal joins are ____.
synovial
What motion does the ligamentum flavum restrict?
flexion
What motion does the interpinsous and supraspinous ligaments restrict?
flexion
What motions do the ALL restrict?
extension and AP translation
What motions do the PLL restrict?
flexion and posterior translation
What are the primary respiratory muscles?
Diaphragm, costals and intercostals, transverse thoracis
What are the secondary respiratory muscles?
scalenes, SP, pectorals, SCM
Where does blood supply to the thorax come from?
posterior branches of the posterior intercostal arteries
Where does venous drainage in the thorax go?
antieor and posterior venous plexuses
What is the ROM for flexion in the thoracic spine?
20-45 degrees
What is the ROM for extension in the thoracic spine?
15-20 degrees
What is the ROM for sidebending in the thoracic spine?
25-45 degrees
What is the ROM for rotation in the thoracic spine?
35-50 degrees
What coupling occurs in the thoracic spine?
Upper- same side
Lower- either way (lower=lumbar=opposite?)
elevation of the ribs in upper thoracic spine = ?
“pump-handle motion”
elevation of the ribs in the lower thoracic spine = ?
“bucket handle motion”
What is the spine of the scapula level with?
SPs of T3
What is the inferior angle of the scapula in line with?
T6-9
How is the medial border of the scapula oriented?
parallel with spinal colum, 5 cm lateral to SPs
Individuals carry their dominant shoulder slightly _____ than the other
lower
The iliac crests are at what spinal level?
L4