Which layer contributes to the profuse bleeding of Scalp

The second layer of the scalp is composed of dense fibrous connective tissue, and this layer houses the main networks of nerves and vessels that enter the scalp from its periphery. The walls of the arteries within the scalp are tightly attached to the surrounding connective tissue bed. When these vessels are severed, they bleed profusely because the fibrous tissue holds apart the cut ends of the severed vessels and does not allow the vessel to retract (as seen in other parts of the body).