Skin
1. Layers
- Epidermis: 0.05-1.5mm
- Dermis: 1-2mm (you said 2mm — correct)
- Hypodermis (fat and connective tissue): variable thickness
Bonus detail: The epidermis has 4 strata (corneum → granulosum → spinosum → basale), and the dermis has papillary (superficial) and reticular (deep) layers.
2. Functions
Barrier (infection, fluid loss, temperature), Thermoregulation (sweating, vascular changes), Tensation (touch, pain, temperature), and vitamin D synthesis (UV → cholecalciferol).