Anatomy and Chemistry Basics
The Integumentary System
The second layer of the skin, the dermis, consists of various connective tissues. As connective tissue, it contains fibroblasts and macrophages within a gelatinous matrix containing collagen, elastic, and reticular fibers. The structure provides strength, extensibility (the ability to be stretched), and elasticity (the ability to return to its original form).
The dermis consists of two layers:
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The papillary layer is a thin, outer layer with fingerlike projections called dermal papillae that protrude into the epidermis. In the hands and feet, the dermal papillae generate epidermal ridges (sweat from the epidermal ridges leaves fingerprints).
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The reticular layer is a thick layer, below the papillary layer, that makes up most of the dermis.
