The dermis layer of skin can bleed.
The skin is composed of three main layers: the epidermis, the dermis, and the hypodermis (subcutaneous layer). While the epidermis is the outermost layer and acts as a protective barrier, it lacks blood vessels. Therefore, superficial cuts that only affect the epidermis do not bleed.
The dermis, located beneath the epidermis, contains blood vessels, hair follicles, sweat glands, and nerve endings. Because of the presence of these blood vessels (arterioles, capillaries, venules), any injury that penetrates the epidermis and reaches the dermis will result in bleeding. The dermis is the layer primarily responsible for providing nutrients and oxygen to the skin and removing waste products via the bloodstream.
The hypodermis, the deepest layer, primarily consists of fatty tissue and larger blood vessels. Wounds that reach this layer can also bleed, and potentially more profusely due to the larger blood vessels found there. However, when generally asked which layer of skin bleeds, the dermis is the correct answer because it is the first layer containing blood vessels directly below the epidermis.
