Eponychium

Eponychium
Nail anatomy, with eponychium labeled as "nail fold".
Longitudinal section through nail and its nail groove (sulcus).
Details
Identifiers
Latin	Eponychium
Dorlands /Elsevier	e_13/12339446
TA	A16.0.01.010
FMA	77859
Anatomical terminology []

In human anatomy, the eponychium [Greek epi (on, upon) + onychion (little claw)], is the thickened layer of skin surrounding fingernails and toenails. It can also be called the medial or proximal nail fold. Its function is to protect the area between the nail and epidermis from exposure to bacteria. The vascularization pattern is similar to that of perionychium.

In hoofed animals, the eponychium is the deciduous hoof capsule in fetuses and newborn foals, and is a part of the permanent hoof in older animals.