rachis
Quick Summary
The rachis is the central shaft of a feather. It is a key component of a feather's structure, from which paired branches called barbs extend. These barbs, in turn, have smaller branches called barbules. When barbules from adjacent barbs hook together, they form a flattened surface known as the vane, which is crucial for flight and body contouring in birds. Feathers, unique to birds, evolved from reptilian scales and serve various functions including insulation, flight, and display.123
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featherā¦of a central shaft (rachis), with serial paired branches (barbs) forming a flattened, usually curved surfaceāthe vane. The barbs possess further branches āthe barbulesāand the barbules of adjacent barbs are attached to one another by hooks, stiffening the vane. In many birds, some or all of the feathers lackā¦
Read Moreā¦of a central shaft (rachis), with serial paired branches (barbs) forming a flattened, usually curved surfaceāthe vane. The barbs possess further branches āthe barbulesāand the barbules of adjacent barbs are attached to one another by hooks, stiffening the vane. In many birds, some or all of the feathers lackā¦
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birdFeathersā¦a tapered central shaft, the rachis, with paired branches (barbs) on each side. An unbranched basal section of the rachis is called the calamus, part of which lies beneath the skin. The barbs, in turn, have branches, the barbules. The barbules on the distal side of each barb have hooksā¦
Read Moreā¦a tapered central shaft, the rachis, with paired branches (barbs) on each side. An unbranched basal section of the rachis is called the calamus, part of which lies beneath the skin. The barbs, in turn, have branches, the barbules. The barbules on the distal side of each barb have hooksā¦
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