ASA Meeting 2013 - Placenta
Placenta Embryology and Circulation
Australian Sonographers Association (ASA) Annual Conference 2013
Educate Innovate Celebrate
|
Draft Page - notice removed when complete.
Introduction
This page will be updated and contain the final conference presentation.
Abstract
Sonographic analysis of the placenta and uterus and their associated blood flow are key diagnostic prenatal assessments in human development. This review will provide an overview of the basic biology of the placentation process and key events in the developmental timeline. This talk should be of value to those wanting a better understanding of the process of human haemochorial placentation.
Placentation begins at the implantation site in the second week of development (GA week 4) with conceptus trophoblast cells invading the maternal endometrial epithelium and stroma. From that time on the process of placentation involves complex interactions between maternal uterine and fetal tissues. While there are many animal models of this process, none currently exactly match that seen in humans.
Maternally, these changes include modification of the maternal vascular, endocrine and immune response. Fetally, an entire organ is grown from extra-embryonic tissue that has many functions outside of acting as a simple exchange tissue. The main maternal vascular changes include increased vascularity and trophoblast modification of spiral arteries. The fetal vascular bed consists of large cord vessels and an exponentially growing capillary bed consisting of kilometres of villous capillaries. Identification of cord vessel number, size and blood flow, are important indices of normal fetal development. Furthermore extensive remodeled of the capillary bed occurs throughout development, with some villi morphologies influencing the efficiency of diffusional gas exchange. Clinically, abnormalities of placentation site, placental development, function and blood flow can have both maternal and fetal ramifications.
The full presentation and additional information/resources/links is available online (http://embryology.med.unsw.edu.au/embryology/index.php?title=ASA_Meeting_2013_-_Placenta).
Historic drawing of Fetus and Placenta
Table 7 De formato foetu liber singularis (1626) by Adriaan van den Spiegel (1578-1625)
Embryo GA Week 4 (Week 2)
<mediaplayer width='250' height='260' image="http://embryology.med.unsw.edu.au/embryology/images/a/a9/Week2_001_icon.jpg">File:Week2_001.mp4</mediaplayer> |
This animation shows the process of implantation, occurring during week 2 of development in humans. The beginning of the animation shows adplantation to the the uterus lining (endometrium epithelium). The hatched blastocyst with a flat outer layer of trophoblast cells (green), the inner cell mass which has formed into the bilaminar embryo (epiblast and hypoblast) and the large fluid-filled space (blastocoel).
|
<mediaplayer width='220' height='260' image="http://embryology.med.unsw.edu.au/embryology/images/0/08/Chorion_001_icon.jpg">File:Chorion 001.mp4</mediaplayer> | Animation shows the events following implantation and focuses on changes in the the spaces surrounding the embryonic disc, the extraembryonic coelom.
The blastoceol cavity is converted into two separate spaces: the yolk sac and the chorionic cavity. The third space lies above the epiblast layer of the embryonic disc, the amniotic cavity.
|
Embryo GA Week 7 (Week 5)
- Embryo Links: Embryo and Placenta | Embryo | Embryo (label) | Embryo (animated) | Embryo (animated large) | Head region | Head region (label) | Body region | Body region (label) | Carnegie stage 13
Embryo GA Week 9 (Week 7)
Embryo in gestational sac | Embryo open sac |
Embryo with placentation (ectopic) | Embryo in amniotic sac |
Placenta Vasculature - MRI and CT
Term placenta viewed from the fetal side.[1]
Magnetic Resonance Angiography (MRA) | Computed Tomography Angiography (CTA) |
Legend
|
References
- ↑ <pubmed>20226038</pubmed>| BMC Physiol.
Glossary Links
- Glossary: A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | Numbers | Symbols | Term Link
Cite this page: Hill, M.A. (2024, June 15) Embryology ASA Meeting 2013 - Placenta. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/ASA_Meeting_2013_-_Placenta
- © Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G