allantois
/əˈlantəʊɪs
/noun (plural allantoides /əˈlantəʊɪdiːz/)
The fetal membrane lying below the chorion in many vertebrates, formed as an outgrowth of the embryo’s gut. In birds and reptiles it grows to surround the embryo; in eutherian mammals it forms part of the placenta.The urachus is a remnant of allantoic origin, connecting the embryonal cloaca to the allantois during early intrauterine life....
- In the fetus, the urachus connects the bladder with the allantois.
- Initially, the bladder is continuous with the allantois.
Derivatives
allantoic
- We're talking about things like the amnion, the chorion, the allantoic sac, the placenta, the umbilical cord, if those words sound familiar to you.
- Veterinarians are completing the study comparing allantoic and amniotic fluids and heart rates of fetuses in mares.
- The embryo forms an allantoic placenta, as is true of at least some peramelids and koalas but not other marsupials.
allantoid
- The spores are white, and are cylindrical to allantoid in shape.
- HvAV - 3a virions vary from allantoid to bacilliform, and are not occluded in occlusion bodies.
- When screening germ plasm for Karnal bunt resistance, allantoid secondary sporidia produced in solid media should be used as inoculum.
Origin
Mid 17th century: modern Latin, based on Greek allantoeidēs 'sausage-shaped'.