BIOL 030 Lecture Notes - Lecture 11: Invagination, Loose Connective Tissue, Capillary Hemangioma
Document Summary
Papillary layer composed of modified areolar ct. Immediately below epidermis, and is the thinner of the 2 dermal layers. Epidermal-dermal junction interdigitation of dermal papillae and epidermal pegs or ridges to prevent side shearing forces from separating the two layers. Dermal papillae fingerlike projections of ct of dermis into epidermis. Thin skin dermal papillae present but are simply rounded bumps or mounds of ct. Reticular layer composed of dense irregular ct and is rich in collagen and elastic fibers. Bundles of collagen fibers interwoven and oriented in all directions to resist shearing. Blood supply derived from arteries in the hypodermis (subcutaneous fascia) Subcutaneous plexus located in the hypodermis. The deepest layer; all the blood supply originates here. Cutaneous plexus located in the dermal-hypodermis junction. Subpapillary plexus located just below the papillary layer. Capillary loops run up into the dermal papillae. A-v shunts control blood flow and are located between cutaneous and subpapillary plexi.