anodermának

Anoderm is the specialized skin lining the anal canal, extending from the dentate line superiorly to the mucocutaneous junction inferiorly. This region is distinct from the epidermis found on the external perianal skin, and also from the rectal mucosa above the dentate line. Anoderm is characterized by its lack of hair follicles, sebaceous glands, and sweat glands, making it appear smooth and pale. It is primarily composed of stratified squamous epithelium that is closely bound to the underlying internal anal sphincter.

The sensory innervation of the anoderm is rich, particularly in its lower portions, contributing to the acute pain experienced with conditions like anal fissures. This sensitivity is a crucial protective mechanism. The anoderm plays a role in fecal continence, not through active muscle contraction, but through its tight seal and sensory feedback. It is also susceptible to various pathologies, including hemorrhoids, anal fissures, anal fistulas, and anal cancer. The distinction between anoderm, perianal skin, and rectal mucosa is important in understanding the clinical presentation and treatment of these conditions.