While walking barefoot on the beach, Joe stepped on a thorn that penetrated through the sole of his foottothe dermis. How many layers of epidermis did the thorn penetrate?
All of the following are true of epidermal ridges except that they
A) extend into the hypodermis. B) increase surface area and friction on fingertips. C) cause ridge patterns on the surface of the skin. D) produce patterns that are determined partially genetically. E) interconnect with the dermal papillae.