- Truncus arteriosus (embryology)
Infobox Embryology
Name = Truncus arteriosus
Latin =
GraySubject = 135
GrayPage = 514
Caption = Heart of humanembryo of about fourteen days. (Truncus arteriosis visible at top.)
Caption2 = Diagrams to illustrate the transformation of thebulbus cordis . Ao. Truncus arteriosus. Au. Atrium. B. Bulbus cordis. RV.Right ventricle . LV.Left ventricle . P.Pulmonary artery .
System =
CarnegieStage =
Precursor =
GivesRiseTo =aorta ,pulmonary artery
MeshName = Truncus+Arteriosus
MeshNumber = A07.541.278.930
DorlandsPre =
DorlandsSuf =
The truncus arteriosus andbulbus cordis are divided by theaorticopulmonary septum .This makes its appearance in three portions.
(1) Two distal ridge-like thickenings project into the lumen of the tube; these increase in size, and ultimately meet and fuse to form a septum (
aorticopulmonary septum ), which takes a spiral course toward the proximal end of the truncus arteriosus. It divides the distal part of the truncus into two vessels, theaorta andpulmonary artery , which lie side by side above, but near the heart the pulmonary artery is in front of the aorta.(2) Four
endocardial cushions appear in the proximal part of the truncus arteriosus in the region of the futuresemilunar valves ; the manner in which these are related to the aortic septum is described below.(3) Two endocardial thickenings—anterior and posterior—develop in the bulbus cordis and unite to form a short septum; this joins above with the aortic septum and below with the ventricular septum. The septum grows down into the ventricle as an oblique partition, which ultimately blends with the ventricular septum in such a way as to bring the bulbus cordis into communication with the pulmonary artery, and through the latter with the sixth pair of
aortic arches ; while the left ventricle is brought into continuity with the aorta, which communicates with the remaining aortic arches.Developmental anomalies
Failure of the truncus arteriosus to close results in the condition known a
Persistent Truncus Arteriosus . One ofcyanotic heart defect s orcongenital heart defects .
=AdditionalExternal links
*
* [http://sprojects.mmi.mcgill.ca/embryology/cvs/early_chambers.html Overview at mcgill.ca]
* [http://www.med.umich.edu/lrc/coursepages/M1/embryology/embryo/13cardiovascular_system.htm Description and diagram at umich.edu]
Wikimedia Foundation. 2010.