Hyponychium

Thickened epithelium underlying the free edge of the nail plate

Hyponychium
Nail anatomy
Details
Identifiers
Latin	hyponychium
TA98	A16.0.01.011
TA2	7073
FMA	77860
Anatomical terminology [edit on Wikidata]

The hyponychium (IPA: /ˌhaɪpoʊˈnɪkiəm/)^[1]^[2] is the area of epithelium, particularly the thickened portion, underlying the free edge of the nail plate on the nail. Its proximal border is immediately distal to distal limit of nail bed—a.k.a. the onychodermal band (the line along the interface of the nail bed and the nail plate). Its distal border the free edge of the nail plate—or where that edge would project downwards onto the epidermis.

It is sometimes called "the quick" (in its archaic meaning of "living"), as in the phrase cut to the quick.^[3]

References

^ "Medical Definition of HYPONYCHIUM". www.merriam-webster.com. Retrieved 2023-07-29.
^ "Definition of HYPO-". www.merriam-webster.com. Retrieved 2023-07-29.
^ "Cut to the quick". Grammarist. 27 September 2018.

Skin and related structures

Skin

Epidermis	Stratum corneum Stratum lucidum Stratum granulosum Stratum spinosum Malpighian layer Stratum basale
Basement membrane	Basal keratinocyte Lamina lucida Lamina densa
Dermis	Papillary Dermal papillae Reticular

Root sheath	Outer root sheath Inner root sheath Henle's layer Huxley's layer
Hair shaft	Cuticle Cortex Medulla Bulb with matrix cells Hair follicle
Muscle	Arrector pili muscle
Pilosebaceous unit	Hair sebaceous gland