Anorectal mucosa and perianal skin

The anorectal mucosa and perianal skin refer to the epithelial linings and outer skin of the terminal gastrointestinal tract, encompassing the anal canal's mucosal zones and surrounding perianal area. The anorectal mucosa includes the colorectal zone with simple columnar epithelium above the pectinate line, transitioning through stratified squamous non-keratinized anoderm, while the perianal skin features keratinized stratified squamous epithelium with hair follicles, glands, and sensory structures.[1][3][4][5] These tissues enable fecal continence via anal sphincters and cushions, defecation through sphincter relaxation, and sensory discrimination of stool consistency for continence control.[1][2][3] In disease, they are implicated in hemorrhoids from cushion enlargement, abscesses from gland infections, fissures, and squamous cell carcinomas arising in perianal skin or anoderm.[1][4][5] No specific drugs directly target these anatomical regions as molecular entities like receptors or enzymes; instead, topical agents treat symptoms like fissures or infections, while surgical interventions address structural issues.[1][4] Their dual endodermal-ectodermal origins influence distinct vascular, neural, and lymphatic supplies, divided by the pectinate line, impacting clinical management of anorectal disorders.[1][3][4]

Other names

Anal mucosa (anoderm)Perianal skin (cutaneous zone)Anus region