The yolk sac is a membranous sac attached to an embryo, formed by cells of the hypoblast layer of the bilaminar embryonic disc. This is alternatively called...

outer side, the amniotic sac is connected to the yolk sac, the allantois, and via the umbilical cord, the placenta. The yolk sac, amnion, chorion, and allantois...

gestational sac is a portion of the conceptus consisting of a cavity between Heuser's membrane and the trophoblast. During formation of the primary yolk sac, some...

the trophoblast. When small, the sac cannot be distinguished from the early normal pregnancy, as there may be a yolk sac, though a fetal pole is not seen...

vitellointestinal duct, the yolk stalk, the omphaloenteric duct, or the omphalomesenteric duct, is a long narrow tube that joins the yolk sac to the midgut lumen...

between two fluid-filled cavities at either end: the primitive yolk sac and the amniotic sac. The epiblast is adjacent to the trophoblast and made of columnar...

Among animals which produce eggs, the yolk (/ˈjoʊk/; also known as the vitellus) is the nutrient-bearing portion of the egg whose primary function is to...

yet capable of feeding themselves and carry a yolk sac which provides stored nutrition. Before the yolk sac completely disappears, the young fish must mature...

envelope. The inner cell mass will give rise to the pre-embryo, the amnion, yolk sac and allantois, while the fetal part of the placenta will form from the...

chorion, allantois, and yolk sac. The amnion and the chorion are the chorioamniotic membranes that make up the amniotic sac which surrounds and protects...

malignancies. There are four main types of OGCTs, namely dysgerminomas, yolk sac tumor, teratoma, and choriocarcinoma. Dygerminomas are Malignant germ cell...

handle liquid waste. The allantois, along with the amnion, chorion, and yolk sac (other extraembryonic membranes), identify humans and other mammals, birds...

Heikinheimo M (Dec 1999). "Transcription Factor GATA-4 Is Expressed in Pediatric Yolk Sac Tumors". American Journal of Pathology. 155 (6): 1823–9. doi:10...

bloodstream to the lungs. Yolk sac tumors grow quickly and recur easily, and are not easily treatable once they have recurred. Stage I yolk sac tumors are highly...

The fetal pole is a thickening on the margin of the yolk sac of a fetus during pregnancy. It is usually identified at six weeks with vaginal ultrasound...

Each primitive aorta anteriorly receives the vitelline vein from the yolk-sac, and is prolonged[clarification needed] backward on the lateral aspect...

for the presence of yolk sac cells within the teratoma. These cells can develop into a frankly malignant tumor known as yolk sac tumor or endodermal sinus...

the remains of the yolk in a yolk sac which continues to nourish the larvae for a few days as they learn how to swim. Once the yolk is consumed, there...

stalk. Here, the gut tube maintains an attachment to the yolk sac. The yolk sac is a membranous sac attached to the embryo, which provides nutrients and functions...

reptiles (amniotes). It develops from an outer fold on the surface of the yolk sac, which lies outside the zona pellucida (in mammals), known as the vitelline...

extraembryonic membranes in birds, reptiles, and mammals: the yolk sac which surrounds the yolk, the amnion which surrounds and cushions the embryo, the allantois...

circulation, the bidirectional flow of blood between the yolk sac and the embryo. The yolk sac is the first extraembryonic structure to appear. This circulation...

become the amniotic sac that provides a protective environment for the developing embryo. The amnion, along with the chorion, the yolk sac and the allantois...

of development but without any transfer of nutrients to the young. The yolk sac is the only source of nutrients for the developing embryo. There are at...

cyst Epidermoid cyst Yolk sac tumor, prepubertal type Testicular neuroendocrine tumor, prepubertal type Mixed teratoma and yolk sac tumor, prepubertal type...

another 20% of cases, there is visualization of a gestational sac containing a yolk sac or an embryo. Ectopic pregnancies where there is visualization...

having a single yolk sac and having a single amniotic sac. However, it is difficult to detect the number of yolk sacs, because the yolk sac disappears during...

expelled; these may include the trophoblast, chorionic villi, gestational sac, yolk sac, and fetal pole (embryo); or later in pregnancy the foetus, umbilical...

hatchling decides to leave the shell, it still has a small sac protruding from its plastron. The yolk sac is vital and provides nourishment while visible, and...

fish are called larvae. They are usually poorly formed, carry a large yolk sac (for nourishment), and are very different in appearance from juvenile and...