right atrium and sinusal

What are the two embryological parts of the right atrium?

Sinusal part – Derived from the right horn of the primitive sinus venosus. Proper (true) part – Derived from the primitive atrium.

What is the shape of the right atrium?

It is cubical in shape.

What forms the anterior wall of the right atrium?

Pectinate muscles, Atrioventricular orifice.

What does the lateral wall of the right atrium contain?

The right auricle.

What is represented by the posterior wall of the right atrium?

The interatrial septum.

What does the inferior wall (floor) of the right atrium contain?

The orifice of the inferior vena cava, The orifice of the coronary sinus.

What is the internal aspect of the sinusal part of the right atrium like?

Smooth walls (no pectinate muscles), Located between the orifices of the superior and inferior vena cava.

What separates the sinusal part from the proper atrial part?

The crista terminalis (a muscular ridge).