Saturday, April 19, 2008
Skin is made up of three layers, some of which contain more specialized cells:
1. Epidermis: is the outer layer of skin. It is made up of 5 layers. From bottom to top they are: stratum basale; stratum spinosum; stratum granulosum; stratum licidum and stratum corneum. The epidermis varies in thickness from .05 to 1.5 mm.
More information about each of these layers can be found here.
The epidermis contains 3 types of specialized cells. Melanocytes which are cells that produce the pigment melanin; Langerhans cells, a type of dendritic cell involved in immune function and Merkel's cells which are associate with sensory touch.
2. Dermis: consists of 3 types of tissue found in two layers; the upper papillary layer and the lower reticular layer . Collagen, elastic tissue and reticular tissue.
The reticular layer (RD) of the skin gives it strength and elasticity. It is also the home to glands and hair follicles. The papillary layer (PD) contains the vascular network important in regulating heat flow from the skin.
Specialized cells in the dermis include: hair follicles, sweat (sebaceous) and scent (apocrine) glands associated with hair follicles; sweat glands (eccrine) not associated with hair follicles, blood vessels and nerves and sensory nerve cells (touch) called Meissner's and Vater-Pacini corpuscles.
3. Subcutaneous tissue: a layer of fat and connective tissue containing blood vessels and nerves.
More articles and resources concerning skin anatomy can be found here.