What is the section of the central rib of a feather that extends past the vane?

The section of the central rib of a feather that extends past the vane is known as the rachis. The rachis serves as the backbone of the feather, running through the center and providing structural support for the vanes, which are the flat, extended parts of the feather that are covered in barbs.

While the quill is the portion of the feather that is embedded in the skin and typically does not extend past the vane, the rachis continues beyond the vanes. Barbs are the smaller structures that branch off from the rachis and form the vane. Understanding the anatomy of feathers, including the relationships between the quill, rachis, barbs, and vanes, is essential in identifying their functions and characteristics in bird anatomy and flight.