Thoracic Wall And Pectoral region Flashcards
Describe the inferior thoracic aperture boundaries
- 12 th thoracic vertebra
- 11th and 12th pair of ribs
- Costal cartilages of ribs 7th - 10th (costal margin)
- Xiphisternal joint
- Closed by the diaphragm
Describe the superior thoracic aperture
Boundaries:
-body of 1st thoracic vertebra
- 1st ribs and their costal cartilages
- jugular notch
What structures pass through superior thoracic aperture?
Structures passing through
-left Subclavian artery
- Subclavian (or SCV) vein
- Brachiocephalic trunk
What are the bones of the thoracic wall?
Vertebrae, ribs, sternum
What are the muscles of the thoracic wall?
Diaphragm, intercostal, pectoral, serratus anterior, latissimus dorsi
What are the nerves and blood vessels of the thoracic wall?
Intercostal neurovascular vessels
Aside from bones, muscles, nerves and bloood vessels, what other structures constitute the thoracic wall?
Skin, subcutaneous tissue, endothiracic fascia,parietal pleura
What are the three main parts of the sternum?
- Manubrium
- Body
- Xiphoid process
What does the sternum articulate with?
- Clavicle
- Costal cartilages I-VII
What is the jugular notch of the sternum?
Small indentation on the superior border if the manubrium
What is manubriosternal joint(angle of Louis) of the sternum?
-Anterior boundary of the transthoracic plane
Corresponds to:
- T4/5 intervertebral disc
- 2nd costal cartilage
Describe typical ribs
- head= 2 Articular facets
- tubercle= 1 Articular facet
- Angle
- Costal groove-for neurovascular bundle
- Sternal end-attached to costal cartilage
Summarize atypical ribs
Ribs 1,2,10, 11,12
- each atypical for their own reason
- Also correspond to the atypical vertebrae
Describe thoracic vertebrae
- small heart shaped body
- round vertebral foramen
- downward slanting spinous process
- Two demifacets on body for articulation with the head of the rib
- A facet on the transverse process for articulation with the tubercle of the rib
Describe the costovertebral joints
Synovial joints between rib and vertebrae
Typical rib articulates with!
-adjacent vertebral body and body of vertebrae above including disk (via Demi facets)
-adjacent transverse process (via facet)
Describe the sternocostal joint
- synovial joints between costal cartilage and sternum (1st rib is fibricartilaginous)
- true ribs attach with sternum directly (via costal cartilage)
- false ribs attach indirectly by joining costal cartilage of rib 7
- Floating ribs don’t attach to
Differentiate true ribs, false ribs and floating ribs
True ribs- 1-7- attach to sternum via own costal cartilage
False- 8-10 attach costal cartilage of rib above
Floating rib- no attachment anteriorly
How are external intercostal fibers oriented?
-fibers- down and medial “hands in front pockets”
How are internal intercostal fibers oriented?
-fibers-down and lateral “hands in back pockets”
How are the fibers of the innermost intercostal oriented?
Fibers- sane as internal
What is the neurovascular bundle of the intercostal muscles?
- intercostal artery, nerve, vein
- between internal and innermost
- innervation is segmental from intercostal nerves
What is the action of the intercostal muscles?
Action: elevation and depression of ribs and maintaining the intercostal space during respiration