The epithelial lining from the dentate line to the intersphincteric groove
The anoderm refers to the epithelial lining of the anal canal located inferiorly to the dentate line and extends for about 1.5 cm. The term andoderm” etymologically comes from the word, anus, and derm” for skin. The anus is that part of the lower orifice of the alimentary canal that ejects feces and flatus. It is the opposite end of an animal’s digestive tract; the other end is the mouth or orifice.
The andoderm lacks hair, sebaceous glands, and sweat glands. And because of that, it is not regarded as a true skin despite that it is made up of squamous epithelium. It is characteristically pale in color, smooth, thin, and delicate. It may also appear shiny when stretched.
The andoderm may be sensitive to abrasion from the use of rough toilet paper and soaps containing chemical irritants, and as such care should be taken when cleaning the area. Since it has tactile and nociceptive nerve endings, pain and itchy sensations may manifest in this area.
Word origin: Greek, combining form of ánō, Latin ānus (ring, anus) + Greek -dermos (–skinned), derivative of dérma (skin)