The ribs Flashcards
what are ribs? what do they form?
The ribs are a set of twelve bones which form the protective ‘cage’ of the thorax
what do ribs articulate with posteriorly and anteriorly?
They articulate with the vertebral column posteriorly, and terminate anteriorly as cartilage
what is the anterior terminate cartilage of ribs called?
costal cartilage
what do the ribs protect?
As part of the bony thorax, the ribs protect the internal thoracic organs
what is the other role of thorax aside from protection?
They also have a role in breathing – during chest expansion the ribcage moves to permit lung inflation
how many classification of ribs are there? what are they?
There are two classifications of ribs – atypical and typical
what is typical rib?
The typical ribs have a generalised structure
what is atypical rib?
atypical ribs have variations on this structure
what do typical ribs consist of?
head, neck, tubercle, shaft
what shape is the head of the typical rib? what does it have?
The head is wedge shaped, and has two articular facets
what are the 2 articular facets separated by?
separated by a wedge of bone
what do the 2 articular facets articulate with?
One facet articulates with the numerically corresponding vertebrae, and the other articulates with the vertebrae above
what does the neck of the rib connect?
The neck contains no bony prominences, but simply connects the head with the body
what is present at the point where the neck meets the body of typical rib?
there is a roughed tubercle, with a facet for articulation with the transverse process of the corresponding vertebrae
what is the structure of the body (shaft) of the rib?
flat and curved
what does the internal surface of the shaft contain? function?
The internal surface of the shaft has a groove for the neurovascular supply of the thorax, protecting the vessels and nerves from damage
which ribs are described as ‘atypical’? why?
Ribs 1, 2, 10 11 and 12 – they have features that are not common to all the ribs
why is rib 1 an atypical rib?
Rib 1 is shorter and wider than the other ribs. It only has one facet on its head for articulation with its corresponding vertebrae (there isn’t a thoracic vertebrae above it). The superior surface is marked by two grooves, which make way for the subclavian vessels
why is rib 2 an atypical rib?
Rib 2 is thinner and longer than rib 1, and has two articular facets on the head as normal. It has a roughened area on its upper surface
what attaches to the roughened area on the upper surface of rib 2?
serratus anterior muscle
why is rib 10 an atypical rib?
Rib 10 only has one facet
what is the facet on rib 10 for?
articulation with its numerically corresponding vertebrae
why are ribs 11 and 12 atypical ribs?
Ribs 11 and 12 have no neck
what is the facet on ribs 11 and 12 for?
articulation with their corresponding vertebrae