Describe the features of the 1st rib which make it atypical

it has one and a half demi facets for articulation

it has a groove for the subclavian artery and vein

also contains a scalene tubercle where the scalene muscle attaches to it from

it attaches to the manubrium of the sternum rather than the body

2. What dermatome is associated with the sternal angle?

T2

3. Describe the course of the internal thoracic artery, the structures it supplies, and identify its terminal branches.

the internal thoracic artery