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The Dermis

Objectives:
  1. Understand the functions of the dermis.
  2. Identify the cellular and structural components of the dermis.
  3. Identify the two regions of the dermis: papillary and reticular.

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Dermis Epidermis - the superficial layer of the skin. Dermis- deep portion of the skin, located just below the epidermis. Papillary region- the superficial region of the dermis containing areolar connective tissue, dermal folds (dermal papillae), networks of capillaries (small blood vessels) and sensory receptors for pain and touch. Reticular region- the deeper portion of the dermis containing dense irregular connective tissue, sudoriferous and sebaceous glands, hair follicles, arteries, veins, and pressure receptors. The hair follicles and glands seen within the reticular region were originally epidermal tissue that became embedded within the dermis. Dense irregular connective tissue- connective tissue rich in collagen fibers that provide structure to the skin. Areolar connective tissue- loose connective tissue consisting of collagen and elastic fibers, fibroblasts, and other cells. It is located just deep to the epidermis. Dermal papilla- finger like projections of the dermis located at the papillary region.

Dermis
The dermis is located deep to the epidermis and helps to anchor the epidermis in place. It consists of various cells, connective tissue, blood vessels, nerves and nerve (sensory) receptors, and blood vessels. The dermis provides support and resiliency to the skin as well as nutrient exchange for the avascular epidermis.

Components
The dermis is composed of connective tissue containing abundant collagen and elastic fibers, adipocytes, fibroblasts, and macrophages (phagocytic white blood cells).

Located within the dermis are nerves and nerve receptors, smooth muscles, glands, hair follicles, and blood vessels.  The blood vessels are involved in thermoregulation and nutrient and gas exchange. The abundant collagen fibers in the dermis provide strength and support, while elastic fibers provide the dermis with its elasticity.

Dermal regions
The dermis consists of the papillary and reticular regions.

Bluedoor Publishing 2011