Tech in Surgery Prep / Unit 3 TSC 059 worked example, 60 to 90 seconds
Layers of the Skin
The idea
The skin has two main layers, the epidermis on the surface and the dermis beneath it, with the hypodermis lying below the skin.
In practice
Work from the surface inward. First, the epidermis is a sheet of keratin-filled cells in four or five layers; it has no blood vessels, its deepest layer makes new cells, and its outermost layer is dead cells that flake away. Second, the dermis is the core of the skin, made of dense connective tissue in two layers, papillary and reticular, and it holds blood and lymph vessels, nerves, hair follicles and sweat glands. Third, below the dermis lies the hypodermis, mostly loose connective tissue and fat, which connects the skin to the deeper tissues.
Where people slip
Bleeding begins in the dermis, because the epidermis has no blood vessels of its own. That is why a skin incision bleeds once it reaches the dermis, and why the first instruments the surgeon needs after the knife are often for control of small bleeders.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
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