Cardiovascular System - Developmental Shunts

From Embryology
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Introduction

Before birth there are three identified "shunts" in the cardiovascular system:

  1. the foramen ovale, within the heart between the atria
  2. the ductus arteriosus, within the aortic arch
  3. the ductus venosus, within the liver


Cardiovascular Links: cardiovascular | Heart Tutorial | Lecture - Early Vascular | Lecture - Heart | Movies | 2016 Cardiac Review | heart | coronary circulation | heart valve | heart rate | Circulation | blood | blood vessel | blood vessel histology | heart histology | Lymphatic | ductus venosus | spleen | Stage 22 | cardiovascular abnormalities | OMIM | 2012 ECHO Meeting | Category:Cardiovascular
Historic Embryology - Cardiovascular 
1902 Vena cava inferior | 1905 Brain Blood Vessels | 1909 Cervical Veins | 1909 Dorsal aorta and umbilical veins | 1912 Heart | 1912 Human Heart | 1914 Earliest Blood-Vessels | 1915 Congenital Cardiac Disease | 1915 Dura Venous Sinuses | 1916 Blood cell origin | 1916 Pars Membranacea Septi | 1919 Lower Limb Arteries | 1921 Human Brain Vascular | 1921 Spleen | 1922 Aortic-Arch System | 1922 Pig Forelimb Arteries | 1922 Chicken Pulmonary | 1923 Head Subcutaneous Plexus | 1923 Ductus Venosus | 1925 Venous Development | 1927 Stage 11 Heart | 1928 Heart Blood Flow | 1935 Aorta | 1935 Venous valves | 1938 Pars Membranacea Septi | 1938 Foramen Ovale | 1939 Atrio-Ventricular Valves | 1940 Vena cava inferior | 1940 Early Hematopoiesis | 1941 Blood Formation | 1942 Truncus and Conus Partitioning | Ziegler Heart Models | 1951 Heart Movie | 1954 Week 9 Heart | 1957 Cranial venous system | 1959 Brain Arterial Anastomoses | Historic Embryology Papers | 2012 ECHO Meeting | 2016 Cardiac Review | Historic Disclaimer

Some Recent Findings

  • Prenatal cardiovascular shunts in amniotic vertebrates[1] "During amniotic vertebrate development, the embryo and fetus employ a number of cardiovascular shunts. These shunts provide a right-to-left shunt of blood and are essential components of embryonic life ensuring proper blood circulation to developing organs and fetal gas exchanger, as well as bypassing the pulmonary circuit and the unventilated, fluid filled lungs. In this review we examine and compare the embryonic shunts available for fetal mammals and embryonic reptiles, including lizards, crocodilians, and birds. These groups have either a single ductus arteriosus (mammals) or paired ductus arteriosi that provide a right-to-left shunt of right ventricular output away from the unventilated lungs. The mammalian foramen ovale and the avian atrial foramina function as a right-to-left shunt of blood between the atria. The presence of atrial shunts in non-avian reptiles is unknown. Mammals have a venous shunt, the ductus venosus that diverts umbilical venous return away from the liver and towards the inferior vena cava and foramen ovale. Reptiles do not have a ductus venosus during the latter two thirds of development. While the fetal shunts are well characterized in numerous mammalian species, much less is known about the developmental physiology of the reptilian embryonic shunts. In the last years, the reactivity and the process of closure of the ductus arteriosus have been characterized in the chicken and the emu. In contrast, much less is known about embryonic shunts in the non-avian reptiles. It is possible that the single ventricle found in lizards, snakes, and turtles and the origin of the left aorta in the crocodilians play a significant role in the right-to-left embryonic shunt in these species."
  • Preferential streaming of the ductus venosus and inferior caval vein towards the right heart is associated with left heart underdevelopment in human fetuses with left-sided diaphragmatic hernia[2] "Left heart underdevelopment is commonly observed in fetuses with left diaphragmatic hernia. This finding has been attributed to compression of the left atrium by herniated abdominal organs, redistribution of fetal cardiac output and/or low pulmonary venous return. As preferential right or left heart underdevelopment is usually not a feature of right diaphragmatic hernia, we searched for an alternative mechanism. Since in normal fetuses the major fraction of left heart filling is provided by the ductus venosus via the inferior caval vein and oval foramen, our study focused in particular on the streaming direction of these structures."

Foramen Ovale

Stage 13 image 068.jpg

Ostium Primum (week 4, stage 13)

Ductus Arteriosus

Ductus Venosus

Week 4 embryo (stage 13) Ductus Venosus
Week 8 Human embryo (stage 22) Ductus Venosus

11254155

8841232

Textbooks

  • Human Embryology (2nd ed.) Larson Ch7 p151-188 Heart
  • The Developing Human: Clinically Oriented Embryology (6th ed.) Moore and Persaud Ch14: p304-349
  • Before we Are Born (5th ed.) Moore and Persaud Ch12; p241-254
  • Essentials of Human Embryology Larson Ch7 p97-122 Heart
  • Human Embryology Fitzgerald and Fitzgerald Ch13-17: p77-111

Molecular

Abnormalities

References

  1. <pubmed>21513818</pubmed>
  2. <pubmed>20702536</pubmed>

Reviews

<pubmed>21513818</pubmed>

Articles

<pubmed>16565980</pubmed> <pubmed>12589721</pubmed> <pubmed>6832717</pubmed>

17984953

Search PubMed

Search Pubmed: heart valve development | cardiovascular shunts



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Cite this page: Hill, M.A. (2024, March 28) Embryology Cardiovascular System - Developmental Shunts. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Cardiovascular_System_-_Developmental_Shunts

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© Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G