Among all the layers of the scalp which layer is highly vascular?

Scalp consists of the overlying soft tissues as well as underlying calvarium. The soft tissues composing the scalp are skin, connective tissue (subcutaneous), aponeurosis (galea aponeurotica), loose areolar connective tissue, and pericranium. The connective tissue layer (subcutaneous) contains the vast majority of the vasculature and nerve supply of the scalp. This layer is laced with strong fibrous reticula that hold the vessels open when the scalp is cut, causing profuse bleeding. The external carotid aery and internal carotid aery provides vessels to the scalp, with extensive anastomoses.