The superficial fascia runs unbroken from scalp to sole — the galea over the skull, the SMAS of the face, the platysma of the neck, the membranous layers of the trunk and limbs — and glides over the deep fascia on a plane of loose, hyaluronan-rich tissue. It is not free everywhere: it is anchored to bone along particular lines, and tethered by fibrous strands and by the perforators that pass through it. Deeper down, the fascia is built more like channels — walls between the muscles, and sleeves around the vessels and nerves, drawn here in gold.
Where a perforator passes through, a sleeve of sliding tissue lets the layers glide past it. Its flow keeps the sleeve wet; a shut vessel would let it dry, and hyaluronan thickens steeply as it crowds, until the sleeve could pin the layers at the vessel — perhaps the dull blocks a stretch meets. A pinned sleeve may stay stuck after its knot lets go, until the layer is moved.
The reports about the fascia seem to belong to this layer: layers that peel apart along lines, places left feeling hollow, and a filling-in felt as re-stitching. Separated layers are known to close again, the way two wet surfaces meet and hold when pressed together, and then to bond for good — fibrin bridging the gap, then collagen.