The systemic circulation is the portion of the circulatory system is the network of veins, arteries and blood vessels that transports blood from heart, services the body's cells and then re-enters the heart, the Mayo Clinic noted. [Image Gallery: The BioDigital Human]
A southern pine (2) 2x12 beam can span 8 feet when supporting joists spanning a maximum of 14 feet, and it can cantilever 2 feet beyond the posts on each side. With the allowable cantilever of the joists, this beam would support a deck 12 feet by 17 1/2 feet.
When I'm unsure of the ability of a 2x12 rim joist on a deck with 2x8 or 2x10 framing to support the load from the stairs, I provide independent support by installing a single-ply header directly beneath the rim joist. The header is screwed to 4x4 posts and bears on 2x4s that are screwed to the 4x4s below the header.