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Chapter 5. Skin Histology Dermis J.F. Thompson, Ph.D. The Dermis - General. primarily irregular dense fibrous conn . tissue variable thickness - thicker on palms and soles; thicker on dorsal surfaces rather than on ventral; thicker on lateral surfaces rather than on medial surfaces
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Chapter 5 Skin Histology Dermis J.F. Thompson, Ph.D.
The Dermis - General • primarily irregular dense fibrous conn. tissue • variable thickness - thicker on palms and soles; thicker on dorsal surfaces rather than on ventral; thicker on lateral surfaces rather than on medial surfaces • few cells present - fibroblasts, macrophages, adipocytes • matrix thick with many protein fibers: collagen, elastin, reticular • the location for blood vessels, nerves and sensory receptors, sweat and oil glands, and hair follicles
Dermis - Structure • Papillary region (layer) - superficial layer - 20% • areolar connective tissue, elastic fibers • dermal papillae – mound-like projections to increase the surface area for nutrition from capillaries • some papillae contain Meissner's corpuscles (for light touch)
Dermis – Structure (cont.) • Reticular region - 80% • dense, irregular fibrous connective tissue • collagen, elastic fibers in a network surrounding the various cells • fibers give strength, elasticity, extensibility • tears in reticular region - "stretch marks“ - long straight red or white streaks
Dermis Papillary and Reticular Regions
End Ch 5 Skin Histology Dermis