Embryology and Congenital Heart Defects Flashcards

A comprehensive vocabulary flashcard set covering cardiac embryology timelines, primitive heart tube structures, septation processes, fetal circulation shunts, adult anatomical remnants, and congenital heart defects based on the lecture transcript.

Endocardium

The inner lining layer of the primitive heart tube.

Cardiac jelly

The gelatin-like middle layer of the primitive heart tube that helps cushion and shape it.

Myocardium

The muscular outer layer of the primitive heart tube that will become the heart muscle.

AV canal (Atrioventricular canal)

The single passage connecting the primitive atrium to the ventricle before splitting into separate passages for the tricuspid and mitral valves.

Sinus Venosus Left Horn

The portion of the sinus venosus that contributes to fetal circulation and eventually forms the coronary sinus.

Sinus Venosus Right Horn

The portion of the sinus venosus that becomes absorbed into the right atrium as the sinus venarum.

Primitive atrium

The region of the primitive heart tube that develops into the right and left atria.

Primitive ventricle

The region of the primitive heart tube that develops into the left ventricle.

Bulbus cordis

The region of the primitive heart tube that serves as the outlet of ventricles and develops into the right ventricle.

Conus

The cardiac region that develops into the crista supraventricularis.

Truncus arteriosus

The upper part of the primitive heart tube that dilates to form the aortic sac and develops into the aorta and pulmonic valves.

Septum primum

A thin wall that grows downward from the roof of the atrium during interatrial septation.

Ostium primum

The initial opening at the bottom of the atrium formed before the septum primum reaches the endocardial cushions.

Ostium secundum

An opening formed higher up in the septum primum by the joining of small holes, maintaining blood flow between the atria.

Septum secundum

A second, thicker wall that grows down next to the septum primum and partially covers the ostium secundum.

Foramen ovale

An oval-shaped hole left by the septum secundum that acts as the second fetal shunt, allowing blood to flow from the right atrium to the left atrium.

Fossa ovalis

The adult structure formed when left atrial pressure increases after birth and seals the foramen ovale shut.

Endocardial cushions

Swellings of soft tissue inside the early AV canal that grow, invade with endocardial cells, and fuse to divide the AV canal into right and left channels.

Interventricular foramen

The opening between the right and left ventricles prior to the growth and fusion of membranous tissues by the end of the 7th week.

Aorticopulmonary septum

A spiral wall formed by the fusion and 180° twisting of neural crest-derived bulbar ridges that splits the truncus arteriosus into the aorta and pulmonary artery.

Ductus venosus

The first fetal shunt; runs within the liver to connect the umbilical vein to the inferior vena cava, allowing oxygenated blood to bypass the liver.

Ductus arteriosus

The third fetal shunt; connects the trunk of the pulmonary artery to the proximal descending aorta, allowing blood from the right ventricle to bypass the collapsed fetal lungs.

Ligamentum venosum

The adult fibrous remnant of the ductus venosus after birth.

Ligamentum arteriosum

The adult fibrous remnant of the ductus arteriosus after birth.

Umbilical vein

The single fetal blood vessel that brings oxygenated blood from the placenta to the fetus.

Umbilical arteries

The two fetal blood vessels that carry deoxygenated blood back from the fetus to the placenta.

Ostium primum ASD

A type of atrial septal defect located in the lower part of the atrial septum near the AV valves.

Ostium secundum ASD

A type of atrial septal defect located in the central part of the atrial septum.

Sinus venosus ASD

A type of atrial septal defect located in the superior interatrial septum.

Perimembranous VSD

The most common type of ventricular septal defect, located in the membranous portion of the interventricular septum near the aortic valve.

Patent Ductus Arteriosus (PDA)

A condition where the ductus arteriosus remains open after birth, shunting blood from the aorta back to the pulmonary artery and potentially causing left ventricular volume overload.

Ebstein's Anomaly

A congenital heart defect characterized by the apical displacement of one or more tricuspid valve leaflets, leading to a smaller functional RV and an atrialized RV.

Tetralogy of Fallot

A congenital heart defect consisting of four related features: VSD, overriding aorta, pulmonary stenosis, and right ventricular hypertrophy.

Endocardial Cushion Defect

Also known as AV canal defect or AV septal defect; an anomaly that can be partial (including ostium primum ASD and cleft mitral valve) or complete (including ASD, VSD, and a common AV valve).

Coarctation of Aorta

A congenital narrowing of the aorta near the origin of the left subclavian artery caused by a shelf-like tissue fold.

Transposition of Great Arteries (TGA)

A congenital heart defect where the great vessel connections are swapped so that the aorta originates from the right ventricle and the pulmonary artery originates from the left ventricle.

Eisenmenger's Syndrome

A condition where a long-standing left-to-right shunt causes pulmonary hypertension, elevated right-sided pressures, and eventual reversal to a right-to-left shunt carrying deoxygenated blood systemically.