Allantois definitions
| Word backwards | siotnalla |
|---|---|
| Part of speech | Noun |
| Syllabic division | al-lan-tois |
| Plural | The plural form of allantois is allantoises. |
| Total letters | 9 |
| Vogais (3) | a,o,i |
| Consonants (4) | l,n,t,s |
The allantois is a membranous sac that is involved in the development of the embryo in reptiles, birds, and mammals. It plays a crucial role in the exchange of gases and waste products between the embryo and the mother. This structure is part of the extra-embryonic membranes that surround the developing embryo within the amniotic egg or placenta.
Structure and Function
The allantois is formed from the endoderm and mesoderm layers of the developing embryo. It starts as an outgrowth of the hindgut and extends into the extra-embryonic coelom, eventually fusing with the chorion to form the chorioallantoic membrane. This membrane is responsible for gas exchange, allowing oxygen to enter the embryo and carbon dioxide to leave.
Development in Different Species
In reptiles and birds, the allantois expands and fuses with the chorion to form a structure known as the allantoic sac. This sac serves as a reservoir for waste materials produced by the embryo, such as uric acid. In mammals, the allantois contributes to the formation of the umbilical cord, connecting the fetus to the placenta for nutrient exchange.
Medical Significance
Understanding the role of the allantois in embryonic development is essential for studying developmental abnormalities and birth defects. Conditions such as omphalocele, where the abdominal organs protrude from the body due to an incomplete closure of the abdominal wall and allantoic remnants, can occur when the allantois fails to properly regress during development.
In conclusion, the allantois is a vital structure in the development of vertebrate embryos, facilitating gas exchange and waste removal to support the growing fetus. Its intricate formation and function underscore its significance in the field of developmental biology and medical research.
Allantois Examples
- The allantois is a structure in developing embryos that helps with waste removal.
- Some reptiles use the allantois to store nitrogenous waste before hatching.
- The allantois plays a crucial role in providing oxygen to avian embryos.
- In mammals, the allantois contributes to the formation of the umbilical cord.
- During pregnancy, the allantois fuses with the chorion to form the chorioallantoic membrane.
- The allantois aids in the exchange of gases necessary for embryonic development.
- Reptiles like snakes rely on the allantois to store uric acid until hatching.
- The allantois is an essential structure for the transport of nutrients in developing embryos.
- Birds utilize the allantois to store uric acid and facilitate gas exchange.
- The allantois is a significant feature in the development of embryos across various species.