The epidermal ridges are formed when the epidermis adapts to the contours of the dermal papillae that are underneath the epidermis.

How are epidermal ridges formed quizlet?

epidermal ridges develop during the third or fourth fetal month as the epidermis conforms to the contours of the underlying dermal papillae of the papillary region. The ridges increase the surface area of the epidermis and thus increase the grip of the hand or foot by increasing friction.

What are the epidermal ridges?

Another feature of some parts of the papillary layer is dermal ridges. These ridges cause ridges in the overlying epidermis, called epidermal ridges. Those ridges and the sweaty marks they leave are what we call fingerprints. ... are places where the dermis has folds to accommodate joint movement.