Septation of the chamber 262-263 Flashcards
Septum primum
Grows toward endocardial cushions, narrowing foramen primum
foramen secundum
forms in septum primum(foramen primum disappears)
Septum secundum
develops as foramen secundum maintains right-to-left shunt
septum secundum
expands and covers most of the foramen secundum. the residual foramen is the foramen ovale
What forms foramen ovale.
Remaining portion of septum primum
what forms the atrial septum
septum secundum and septum primum
what causes the foramen ovale to close soon after birth
the increase pressue in the LA
patent foramen ovale
caused by failure of septum primum and septum secundum to fuse after birth; most are left untreated, and can lead to paradoxical emboli( venous thromboemboli that enters systemic arterial circulation), similar to those resulting from an ASD
what forms interventricular foramen
muscular interventricular septum
What forms membranous interventricular septum
aorticopulmonary septum rotates and fuses with muscular ventricular septum
VSD
most common congenital cardiac anomaly, usually occurs in membranous septum.
what contributes to atrial spetation and membranous portion of the interventricular septum
Growth of endocardial cushions separates from atria from ventricles
conotruncal abnormalities associated with failure of neural crest cells to migrate.
Transposition of great vessels.
Tetralogy of fallot
persistent truncus arteriosus
what forms the aorticopulmonary septum
Truncal and bulbar ridges that spiral and fuse.
Aortic/pulmonary
derived from endocardial cushions of outflow tract
Valvular anomalities may be stenotic, regurgitant, atretic(e.g tricuspid atresia), or displaced(e.g Ebstein anomaly)