Skin

The skin is the largest organ of the body and serves as a barrier between the animal and its environment. It plays critical roles in protection, sensation, thermoregulation, immune defense, and vitamin D synthesis.

The skin is typically described in three anatomical layers:

• The Epidermis is the outermost layer, composed of stratified squamous keratinized epithelium, witch functions in protection and waterproofing. It contains specialized cells: keratinocytes, melanocytes, and Langerhans cells;

• The Dermis [Corium] is a dense layer of connective tissue, divided into papillary and reticular layers, housing the blood vessels, nerves, lymphatic vessels, hair follicles, sebaceous and sweat glands;

• The Subcutaneous tissue [Hypodermis] is a layer of loose connective tissue and fat beneath the dermis. It allows mobility of the skin and provides insulation and energy storage.