A proctodeum is the back ectodermal part of an alimentary canal.
It is created during embryogenesis by a folding of the outer body wall.
It will form the lower part of the anal canal, below the pectinate line, which will be lined by stratified squamous non-keratinized (zona hemorrhagica) and stratified squamous keratinized (zona cutanea) epithelium.
The junction between them is Hilton's white line.
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