LL2.H1.3 +D1 Skin Appendages: Nails
Skin Appendages: Nails:
- Nails are made up of specialised keratinised epidermal cells which contain hard keratin: the cells of the stratum corneum of the skin contain soft keratin
- Nails initially develop towards the end of the first trimester of pregnancy as an ingrowth of epithelial cells into the underlying connective tissue
- Nail growth occurs mainly at the thickened proximal end of the nail bed by rapid proliferation of epithelial cells which are continuous with the stratum germinativum of the epidermis
- The keratinised cells of the nail plate do not desquamate
- The epidermis beneath the nail plate consists of only the deeper layers of the epidermis and is called the nail bed
- There are no sweat glands or hair follicles in the nail bed
- Cells of the stratum corneum of the epidermis which extend over the free surface of the nail plate form the cuticle (or eponychium)
Diagram of Nail:
