Skin of the trunk
Cutis trunci
Integumentary (skin)SkinWhole body
- What it is
- The skin of the chest, abdomen, back, shoulders and buttocks, showing the relief of the clavicles, pectoral muscles, rectus abdominis, umbilicus, inguinal grooves, spine furrow, scapulae, deltoids and buttocks.
- Function
- Barrier against water loss, microbes and UV; thermoregulation through sweat and blood flow; touch, pressure and pain sensing; vitamin D synthesis.
- Size
- Largest part of the ~1.8 m² body surface (trunk ≈ 36 % by the rule of nines); 1–2 mm thick on the front, up to ~4 mm on the upper back
- Clinical note
- The skin of the back has the thickest dermis in the body. Skin tension (Langer) lines run mostly horizontally on the trunk, so horizontal incisions heal with finer scars.