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Figure 2.4 Hemidesmosome. (Source: Reprinted
from Tortora and Derrickson, 2006.) |
This is a specialised area of the skin consisting of a number of different layers and structures which ensure that the dermis and the epidermis are held together. Hemidesmosomes anchor keratinocytes to the basement membrane. These are similar to desmosomes but only have one plaque attached to the glycoprotein integrin outside the plasma membrane and attached to laminin in the basal lamina (lamina lucida) (Figure 2.4). The corrugated shape of the basement membrane zone helps to ensure that the rete ridges of the epidermis interdigitate with the dermal papillae providing further stability.
The effectiveness with which the two layers of the skin hold together can be compromised in some genetically inherited disorders, for example epidermolysis bullosa, or by diseases that develop later in life, for example bullous pemphigoid (see
Less common skin conditions for further details).
