Chapter 6: Dermis, Lines of Cleavage and Strech Marks, Subcutaneous Layer

What is the dermis?

• Deep to epidermis

• composed of CT proper

• other structures present: blood vessels, sweat glands, sebaceous glands, hair follicles, nail roots, sensory nerve endings, arrector pili, motile dendritic cells

What is the papillary layer of the dermis?

• superficial region of dermis (named for projections of dermis)

• deep to epidermis

• areolar connective tissue

• dermal papillae

• interlock with epidermal ridges to increase area of contact between layers

What is the reticular layer of the dermis?

• deeper

• major portion of dermis

• dense irregular connective tissue

What are lines of cleavage?

• collagen and elastic fibers oriented in parallel bundles at specific locations

• Bundles function to resist stress during routine movement

What is the orientation indicated by lines of cleavage?

• incisions parallel to cleavage lines more likely to heal quickly

• incisions perpendicular to cleavage lines are more likely to open due to cut elastic fibers

What causes stretch marks?

• skin is stretched beyond its capabilities, results in striae

• some collagen fibers torn

What is the subcutaneous layer?

• hypodermis, superficial fascia

• Not part of integument, areolar and adipose CT

F: protection, energy storage, and insulation, common drug injection site, extensive vascular network promotes rapid absorption, thickness/distribution influenced by sex hormones