Thoracic Cavity: Osteology Flashcards
How do independent & demi-faceted vertebra differ?
Which thoracic vertebra are independent and which are demi-faceted?
Independent vertebra have a single facet for head of rib, while demi-faceted have 2 (superior & Inferior).
Demi-faceted also have a transverse facet which articulates with the rib tubercle.
Independent: T1, T9-12
Demi-faceted: T2-T8
What is the purpose of the Costal Cartilage?
Connect ribs to sternum and provide flexibility, which is critical for respiration.
What is the costal groove?
Where is it located and what are the contents?
The costal groove is a groove on the inferior portion of the shaft of the ribs containing the intercostal vein, artery, & nerve.
How do true, false, & float ribs differ?
Identify which ribs fall into each category.
True ribs articulate with the sternum via 1 independent costal cartilage, while false ribs articulate with the sternum via the costal cartilage of another rib (piggy-backing).
Floating ribs are small, do not completely wrap around the torso, and do not articulate with the sternum at all.
True Ribs: 1-7
False Ribs: 8-10
Floating Ribs: 11-12 (sometimes 10)
Describe the structure of the Sternum
The sternum is comprised of (3) bones which (eventually) fuse together to make the sternum; The Manubrium, Sternal Body, & Xiphoid process.
What other structures does the Manubrium articulate with?
What other notch is present on the superior portion of the Manubrium?
The Manubrium articulates with;
The clavicles at the superior clavicular notches
The 1st Rib set at the Lateral 1st Costal notches
1/2 of 2nd Rib set at the inferior 2nd notches
The Sternal (Jugular) notch
What is the resulting structure following the fusion of the Sternal body & Manubrium?
The sternal angle marks the line dividing the superior & inferior mediastinum. The 2nd Costal notch also fuse together at this point.
Identify the vertebral level landmarks of the sternum.
- Jugular notch: Intersects between T2 & T3
- Sternal Angle: Intersects between T4 & T5
- Also serves as a landmark to count ribs, as the 2nd rib articulates at the sternal angle.
- Xiphosternal joint: Intersects with the body of T9
Identify the Joints of the Thorax
What do all these joints facilitate?
- Costovertebral: Vertebra body & Head of Rib
- Costotransverse: Transverse process of vertebra & Transverse tubercle of Rib
- Sternocostal: Costal Cartilage & Sternal body
- Costochondral: Costal Cartilage & shaft of Rib
- Sternoclavicular: Manubrium & Clavicle
- Manubriosternal: Manubrium & Sternal Body
- Xiphisternal: Xiphoid process & Sternal Body
Large amount of articulation facilitates flexibility for respiration
