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...
8 KB (972 words) - 21:55, 3 May 2024
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...
10 KB (1,167 words) - 16:20, 17 August 2024
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...
7 KB (736 words) - 16:31, 14 February 2024
Blighted ovum (redirect from Empty sac)
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...
6 KB (511 words) - 03:59, 8 April 2024
Vitelline duct (redirect from Yolk-stalk)
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...
4 KB (431 words) - 00:17, 12 July 2024
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...
11 KB (1,404 words) - 13:51, 29 August 2023
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...
18 KB (2,240 words) - 14:58, 28 February 2024
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...
18 KB (2,240 words) - 14:29, 22 July 2024
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...
43 KB (5,259 words) - 16:16, 15 August 2024
Fetal membranes (section Yolk sac)
chorion, allantois, and yolk sac. The amnion and the chorion are the chorioamniotic membranes that make up the amniotic sac which surrounds and protects...
16 KB (1,893 words) - 02:46, 30 April 2024
Ovarian germ cell tumors (section Yolk sac tumor)
malignancies. There are four main types of OGCTs, namely dysgerminomas, yolk sac tumor, teratoma, and choriocarcinoma. Dygerminomas are Malignant germ cell...
29 KB (3,067 words) - 05:15, 8 August 2024
Allantois (category Amniotic sac)
handle liquid waste. The allantois, along with the amnion, chorion, and yolk sac (other extraembryonic membranes), identify humans and other mammals, birds...
8 KB (873 words) - 16:19, 17 August 2024
Endodermal sinus tumor (redirect from Yolk sac tumor)
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...
9 KB (887 words) - 11:14, 23 January 2024
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...
198 KB (21,173 words) - 08:34, 23 August 2024
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...
850 bytes (82 words) - 12:39, 16 August 2023
Each primitive aorta anteriorly receives the vitelline vein from the yolk-sac, and is prolonged[clarification needed] backward on the lateral aspect...
2 KB (199 words) - 14:31, 14 August 2023
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...
46 KB (5,012 words) - 18:11, 20 August 2024
Egg (section Egg size and yolk)
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...
42 KB (4,715 words) - 23:29, 22 August 2024
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...
12 KB (1,416 words) - 12:41, 14 May 2024
Chorion (redirect from Chorionic sac)
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...
11 KB (1,223 words) - 16:18, 17 August 2024
extraembryonic membranes in birds, reptiles, and mammals: the yolk sac which surrounds the yolk, the amnion which surrounds and cushions the embryo, the allantois...
2 KB (266 words) - 14:51, 11 December 2023
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...
49 KB (6,218 words) - 19:52, 18 June 2024
Amnion (category Amniotic sac)
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...
9 KB (1,207 words) - 16:18, 17 August 2024
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...
35 KB (3,536 words) - 12:22, 9 July 2024
cyst Epidermoid cyst Yolk sac tumor, prepubertal type Testicular neuroendocrine tumor, prepubertal type Mixed teratoma and yolk sac tumor, prepubertal type...
63 KB (6,753 words) - 05:21, 18 August 2024
another 20% of cases, there is visualization of a gestational sac containing a yolk sac or an embryo. Ectopic pregnancies where there is visualization...
70 KB (7,901 words) - 13:09, 9 July 2024
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...
9 KB (905 words) - 03:19, 8 August 2024
expelled; these may include the trophoblast, chorionic villi, gestational sac, yolk sac, and fetal pole (embryo); or later in pregnancy the foetus, umbilical...
112 KB (11,001 words) - 21:13, 23 August 2024
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...
48 KB (5,078 words) - 14:45, 30 July 2024
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...
62 KB (6,472 words) - 17:16, 3 August 2024