What does allantoic mean?
Allantoic is a technical adjective used almost exclusively in embryology, developmental biology, and veterinary medicine to describe anything relating to the allantois — one of the extraembryonic membranes that develops alongside the embryo in reptiles, birds, and mammals. The allantois serves primarily as a repository for metabolic waste and, depending on the species, plays a major role in respiration: in birds and reptiles it fuses with the chorion to form the chorioallantoic membrane, which exchanges gases through the eggshell, while in placental mammals it contributes substantially to the formation of the umbilical cord and the fetal portion of the placenta. Common phrases include allantoic cavity, allantoic fluid, and allantoic membrane. The word carries a purely scientific register with no figurative or colloquial use, making it valuable chiefly to students and professionals in the life sciences rather than general readers.
adjectiveRelating to the allantois, an embryonic membrane involved in waste storage and gas exchange in reptiles, birds, and mammals. More broadly, of or characteristic of the allantois or its functions.
- Relating to the allantois, an embryonic membrane involved in waste storage and gas exchange in reptiles, birds, and mammals.
- Of or characteristic of the allantois or its functions in embryonic development.
"The allantoic cavity expands rapidly during early embryonic development in birds."
"In birds, the allantoic membrane fuses with the chorion to facilitate gas exchange through the eggshell."
"Researchers measured the volume of allantoic fluid at each stage of gestation in the mouse embryos."
Before your placenta existed, an early version of you had a sac called the allantois doing the dirty work — and 'allantoic' is what scientists call everything about it.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of allantoic
Allantoic derives from the Greek word 'allantoeides', meaning sausage-shaped, from 'allant-' (allantos, meaning sausage) combined with the suffix '-eides' (resembling). The term was adopted into New Latin as 'allantois' to name the embryonic membrane, and the adjective allantoic was formed from it. It entered scientific English usage in the 19th century as embryology matured as a discipline. Related terms sharing the same Greek root include allantois itself and the compound chorioallantoic.
Related word forms
How allantoic is actually used
Strictly a technical term used in embryology, developmental biology, veterinary medicine, and comparative anatomy. It is not used in everyday speech and carries no figurative or informal senses.
Easily confused with allantoic
Amniotic refers to the amnion, the innermost membrane surrounding the embryo in protective fluid, whereas allantoic refers to the allantois, a separate membrane involved in waste storage and gas exchange.