A proctodeum is the back

ectodermal The ectoderm is one of the three primary germ layers formed in early embryonic development. It is the outermost layer, and is superficial to the mesoderm (the middle layer) and endoderm (the innermost layer). It emerges and originates from t ...

part of an alimentary canal. It is created during

embryogenesis An embryo is an initial stage of development of a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male sperm ...

by a folding of the outer body wall. It will form the lower part of the

anal canal The anal canal is the part that connects the rectum to the anus, located below the level of the pelvic diaphragm. It is located within the anal triangle of the perineum, between the right and left ischioanal fossa. As the final functional segment ...

, 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 The anocutaneous line, also called the Hilton white line or intersphincteric groove, is a boundary in the anal canal. Below the anocutaneous line, lymphatic drainage is to the superficial inguinal nodes. The anocutaneous line is slightly below t ...

External links

* Embryology of digestive system {{developmental-biology-stub