What is the bony thorax made up of?
- The thoracic vertebrae posteriorly
- The ribs and intercostal spaces laterally
- The sternum and costal cartilages anteriorly
What happens to the thoracic cage superiorly?
It is continuous with the neck, at the thoracic inlet
What happens to the thoracic cage inferiorly?
The diaphragm separates it from the abdominal cavity
How many ribs are there?
What do the ribs articulate with posteriorly?
The vertebral column
How do the ribs articulate with the vertebral column?
Via the costo-vertebral joints
What do the ribs articulate with anteriorly?
- Ribs 1-7 are connected to sternum
- Ribs 8-10 are connected to costal cartilage alone
- Ribs 11-12 have ends free in the abdominal muscles
How do ribs 1-7 connect to the sternum?
Via costal cartilages
What are ribs 11 and 12 known as?
What ribs are considered 'typical'?
What do typical ribs have?
What does the head of the rib have?
Two articular facets
What are articular facets at the head of the rib for?
Articulation with the body of the corresponding vertebrae, and the vertebrae above
What does the neck of the rib do?
Connects the head of the rib with the body
At what level does the neck of the rib connect the head and the body?
The level of the tubercle
What does the tubercle of the rib contain?
One articular facet
What is the purpose of the articular facet of the tubercle of the rib?
For articulation with the transverse processes of the corresponding thoracic vertebrae
What shape is the shaft of the rib?
Thin, flat, curved
What happens at the angle of the rib?
The shaft twists forward to form its characteristic curve
What does the shaft contain?
A costal groove
Where is the costal groove located?
Close to the lower border of the shaft of the rib
What does the costal groove do?
Protects the intercostal vessels and nerve
Label this diagram of a typical rib
- A - Crest of head
- B - Superior articular facet
- C - Tubercle
- D - Angle
- E - Cup for costal cartilage
What are the typical features of most thoracic vertebrae?
- Have bodies, vertebral arches and seven processes
What are the 7 processes of the thoracic vertebrae for?
Muscular and articular connections
What are the characteristic features of thoracic vertebrae?
- Bilateral costal facets (demifacets)
- Costal facets
- Spinous processes
Where do the demifacets of thoracic vertebrae occur?
On the vertebral bodies, usually occuring in inferior and superior pairs
What is the purpose of the vertebral body demifacets?
Articulation with the heads of ribs
Where are the costal facets of thoracic vertebrae found?
On the transverse processes
What is the purpose of the costal facets of thoracic vertebrae?
Articulation with the tubercles of the ribs