Thoracic Vertebrae (Quiz 2/Test 2) Flashcards
What are the characteristics of the thoracic vertebrae?
-long, thin, angulated SP
-costal articular facets on body (superior and inferior demi facets)
-costal articular facets on the transverses (costal transverse facets)
What is the difference between typical and atypical thoracic vertebrae?
variations in rib articulations
What are the typical thoracic vertebrae?
T2-T8
What are the true ribs?
ribs 1-7
-direct attachment to sternum via costal cartilage
What are false ribs?
ribs 8-10
-indirect attachment to sternum via costal cartilage
-attached to TPs
What are floating ribs?
ribs 11/12
-not attached to sternum
-not attached to TPs
What shape is the body of thoracic vertebrae?
test q
heart shaped, concave sided cylinder
How many demi facets are there on thoracic vertebrae?
2 pairs of costal demi facets (1/2 facets)
Do the superior and inferior epiphysis of thoracic vertebrae have any features?
no, theyre flat and featureless
What does the posterior surface of thoracic vertebrae show?
basi-vertebral foramen
What shape are the superior demi facets and where are they located on thoracic vertebrae?
-small crescent shaped surfaces
-located on the postero-supero-lateral corner of the body
-may be slightly elevated
What shape are the inferior demi facets and where are they located on thoracic vertebrae?
-small crescent shaped surfaces
-located on the postero-infero-lateral corner of the body
-often slightly raised
Superior and inferior demi facets align where on thoracic vertebrae?
on successive vertebrae
-inferior demi facet aligns with the superior demi facet below
-forms full facet for articulation of a rib head
-rib number = same number as LOWER vertebra
What are the features of the pedicles on thoracic vertebrae?
-short thick vertical plates
-half as tall as body
-little or no superior pedicle notches
-deep inferior pedicle notches
-the notches form large oval IVFs facing directly laterally
Where do the pedicles of thoracic vertebrae project?
posteriorly from the upper corners of the body
Where do the pre-zygopophyses of thoracic vertebrae project?
posterosuperiorly from the top of the pedicles
What do the pre-zygopophyses of thoracic vertebrae form?
the posterior margins of the IVFs
What shape are the superior articular surfaces of thoracic vertebrae? What do they cover?
-flat smooth tall ovals
-cover the entire posterior surface of the pre-zygopophyses
Where do the superior articular surfaces of thoracic vertebrae face?
mainly posteriorly, slightly superolaterally
What are the characteristics of TPs on thoracic vertebrae?
-thick strong cylinders (wide base, narrow neck, bulbous distal head)
-act as support braces for ribs 1-10
Where do the TPs of thoracic vertebrae project?
-posterolaterally and superior from the LPJ
What shape are the costal transverse facets on thoracic vertebrae? Where are they found?
-round concave articular facet
-found on T1-10 TPs
-located on the anterior transverses in the upper thoracics
-located higher on the transverses in the lower thoracics
What do the costal transverse facets of thoracic vertebrae articulate with?
rib tubercles
What are the characteristics of laminae on thoracic vertebrae?
-very thick vertical plates of bone
-overlap the subjacent laminae (like roof shingles)
-meet/fuse (line of interlaminar fusion), form the base of the spinous
-marginal bony spikules are ligament attachments
-post zygopophyses has slight lateral flaring off of the laminae
Where do the laminae of thoracic vertebrae project?
-inferomedially from the pedicles
What are the features of the inferior articular surfaces of thoracic vertebrae?
-flat, smooth, tall ovals
-mostly on the anterior laminae
-lateral edge on the post-zygopophysis
Where do the inferior articular surfaces of thoracic vertebrae face?
-anteriorly, slightly inferomedially
What are the characteristics of the SP on thoracic vertebrae?
-very long, slender, tapered
-sharp superior ridge, broader underside
-ends in a swollen pointed distal spinous tubercle
-neural canal is small and round
Where do the SPs of thoracic vertebrae project?
posteroinferiorly at varying angles
What shape is the neural canal in thoracic spine?
test q
small and round
T1 is a cervicothoracic transitional vertebra that is mostly typical except it has some atypical features. What are the atypical features?
-body is more heart shaped, less rectangular
-TPs project slightly posterolaterally
-SP is shorter and less angulated
-no superior demi-facets
-has full costal facets that articulate with L/R heads of rib 1
-rib 1 will have only one facet on head
typical part
-inferior demi facets articulate with L/R heads of rib 2
T9 is completely typical EXCEPT,
there are no inferior demi facets
Which thoracic vertebra begins thoracolumbar transition?
T10
What makes T10 atypical?
-the body has no superior or inferior demi facets and instead has full superior costal facets that are in the same location as typical superior demi facets
-articulates with L/R heads of rib 10 (ribs 10-12 only have one facet on head)
-SP is shorter and less angulated
What makes T11 atypical?
theres a lot
-body is less heart shaped and more kidney shaped like lumbars
-body has no superior or inferior demi facets, and instead has full superior costal facets (L/R heads of rib 11)
-post zygopophyses are more prominent and project downward from laminae
-inferior articular surfaces are slightly convex and face slightly anterolaterally
-SP is short, leveled, and rectangular
-TPs are much smaller/shorter
-TPs dont have costal transverse facets
-ribs 11/12 are not supported by TPs or sternum (ribs are short with no neck or tubercle and are referred to as floating ribs or false ribs because they’re not directly attached to sternum)
What is the most atypical thoracic vertebra?
T12
What makes T12 atypical?
theres a lottttttt
-very similar to lumbars
-body is kidney shaped
-body is massive compared to the arch
-body does not have superior or inferior demi facets and instead has full superior costal facets (L/R heads of rib 12)
-vertebral arch is proportionally small
-few muscles are attached at vertebral arch
-T12 has a thoraco-lumbar swivel joint called the point of inflexion or kapandji
-TPs are small and dont project much
-TPs do not have costal transverse facets
-TPs consists of 3 small tubercles (superior tubercle is the largest)
-superior articular processes face more posteromedial and become concave LM
-SP is short and blocky
-SP is leveled
-post zygopophyses projects prominently downward from the laminae
-inferior articular surfaces face more anterolaterally and become more convex
The superior tubercle of the TPs of T12 are the largest. Where do they project?
superolaterally from the LPJ, along side the lateral margin of the pre-zygopophysis
Which tubercle on the TPs of T12 is considered a true transverse tissue?
superior tubercle
What is the superior tubercle of the TPs of T12 homologous to?
test q
lumbar MP
Which tubercle on the TPs of T12 is the smallest (small pointed bump)?
lateral tubercle
Where does the lateral tubercle of the TPs of T12 project?
laterally from the LPJ
What is the lateral tubercle of the TPs of T12 homologous to?
lumbar transverse
Where does the inferior tubercle of the TPs of T12 project?
infero-laterally from the LPJ
Which 2 tubercles of the TPs of T12 are considered costogenic tissue?
lateral and inferior tubercle
What is the inferior tubercle of the TPs of T12 homologous to?
lumbar accessory process
What do all atypical thoracic vertebrae have in common?
missing demi facets!
