Embryology of the Left Atrium

What structure is formed when the endocardial cushions fuse in the 5th week?

What does the septum intermedium divide in the atrioventricular canal?

What structure arises from the roof of the primitive atrium at the end of the 4th week?

What is created by the fusion of right and left atrioventricular orifices?

Which structure divides the AVC into superior and inferior parts?

What forms the valve of the foramen ovale?

Which part of the left atrium is derived from the primitive pulmonary vein?

What does the free edge of the septum secundum form?

Where does the pulmonary vein arise from?

What constitutes the floor of the fossa ovalis?

What is the communication between the primitive atrium and the ventricle called?

What happens to the left horn of the sinus venosus as a result of the enlargement of the right horn?

During which week does the partition of the atrioventricular canal (AVC) start?

Where does the sinuatrial opening shift as a result of the enlargement of the right horn of the sinus venosus?

What are the bulges that appear on the ventral and dorsal walls of the atrioventricular canal in the 4th week called?

What is formed by the left horn of the sinus venosus as it decreases in size?

When do the endocardial cushions extend towards each other to form the septum?

What happens to blood flow due to the obliteration of the left vitelline, umbilical, and common cardinal veins?

What is initially circular in shape but later becomes flattened?

Which structure receives all the blood from the embryo and placenta?

What structure arises from the roof of the primitive atrium just to the right of the septum primum?

What is formed when the perforations in the septum primum coalesce?

Which part of the septum secundum forms an incomplete partition of the atrium?

What happens to the cranial part of the septum primum?

Which structure is pressed against the septum secundum to form the floor of the fossa ovalis?