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Princess Maranda posted an update in the group
Histology Art (MT 30 – J) 4 years, 2 months ago The integument, composed of skin and its appendages, sweat glands, sebaceous glands, hair and nails, is the largest organ, constituting l6% of the body weight.
The skin is composed of the epidermis, an epithelial layer of ectodermal origin, and the dermis, a layer of connective tissue of mesodermal origin.Thick skin covers the palms and soles. The epidermis of thick is characterized by
the presence of all five layers of cells. Thick skin lacks hair follicles, muscles, and
sebaceous glands but does possess sweat glands.Thin skin covers most of the remainder of the body. The epidermis has a thin
stratum corneum and lacks a definite stratum lucidum and stratum granulosum,
although individual cells of these layers are present in their proper locations.
The distal end of each digit is protected by a strong plate of hard keratin, called a nail or nail plate, which grows out from a nail bed. The nail bed, is a specialised form of skin epithelium, and has the same four layers of the epidermis of skin, with the nail plate being analogous to the stratum corneum layer.The nail plate is made up of tightly packed, hard, keratinized epidermal cells. It has a nail body, a free edge, and extends deep into the dermis at the proximal end to form the nail root (or nail groove).
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