Thoracic Spine and Thorax/Chest Wall Flashcards
Function of the Thoracic Region
Stability
What serves the stability of the Thoracic region?
Due to structure:
-rib cage
-spinous processes
-vertebral bodies
-static restraints
Thoracic Body
Wedge-shaped Posterior height greater than anterior height
2 demifacets (half facets) for articulation with ribs
Peak anteroposterior height difference occurs…
at T7
What does the anterior wedging of the body produce?
The normal kyphotic posture of the TS
Arches of the TS vertebrae
Pedicles: face posteriorly
Laminae: short, thick, broad
Superior facets: thin, flat (face posterior, superior, lateral)
Inferior facets: thin, flat (Face anterior, inferior, medial)
Transverse processes: large, thickened ends (paired oval facets, decrease in length caudally)
Spinous processes: T1-10 (slope inferiorly, T11-12(triangular shape)
Vertebral foramen: small, circular
IVD of the TS vertebrae
Thinner
Smaller ratio of disc size: vertebral body size
Supports the function of stability over mobility
Annulus fibrosis (outer fibers)
Resists distraction, translation, and rotation of vertebral bodies
Anterior Long. Ligament
Limits extension
Reinforces anterolateral annulus, anterior aspect of IV joint
(thicker than at CS)
Posterior Long. Ligament
Limits forward flexion
Reinforces posterior annulus
Ligamentum Flavum
Limits forward flexion, particularly in lumbar region
(thicker than at CS)
Supraspinous Ligament
Limits forward flexion
Intertransverse Ligament
Limits forward flexion, CL flexion
Zygapophyseal Joint Capsule
Resists forward flexion, axial rotation
TS Interbody Joints
Between flat vertebral surfaces
Allow for translations in all planes
Discs allow for small amounts of tilting
TS Zygapophyseal Joints
Plane synovial joints
-Tighter joint capsule compared to CS and LS
Lie approx. 60 deg off the transverse plane and 20 deg off the frontal plane OVERALL
-Somewhat dependent on region of thoracic spine
Orientation of Zygapophyseal Joints of the TS
Inferior facets of SUPERIOR vertebrae: Anterior, inferior, medial
Superior facets of INFERIOR vertebrae: Posterior, superior, lateral
Each thoracic vertebra articulates with a set of paired ribs by way of two joints. What are they?
The costovertebral and the costotransverse joints.
What are the vertebral components of the costovertebral joints?
The demifacets located on most of the vertebral bodies
What are the vertebral components of the costotransverse joints?
The oval facets on the transverse processes
Thorax
Describes the bones of the rib cage, the fascia and muscles that attach to the rib cage, the visceral organs within the rib cage, and even the skin that covers the rib cage
Rib Cage (thoracic cage or the bony thorax)
Consists of the thoracic vertebrae, the ribs, and the sternum
What does the rib cage protect?
Heart, lungs and viscera
What does the process of ventilation, including inhalation/exhalation(inspiration/expiration) depend on?
Depends on the mobility of the rib cage and the ability of the muscles of ventilation to move it