Pectinate Line

**Semantic type:** Embryonic Structure

**Definition:** An anatomical line of demarcation that separates the upper and lower part of the anal canal, both in structure and neurovascular supply, reflecting the different embryologic origin; superior to the line the epithelium is a mucous membrane like the rest of the gastrointestinal tract and inferiorly the epithelium is considered cutaneous, and is composed of stratified squamous keratinized with hair and sebaceous glands.

**Synonyms:** - Dentate Line