Anatomy of Atrial Appendages

Questions and Answers

They insert into the crista terminalis at an oblique angle.

They run all the way round the atrio-ventricular junction. (correct)

They are absent in the right atrial appendage.

They are confined within the appendage.

Hyparterial bronchi with three-lobed lungs.

Eparterial bronchi with three-lobed lungs. (correct)

Eparterial bronchi with bilobed lungs.

Hyparterial bronchi with four-lobed lungs.

Isomeric situs.

Situs solitus.

Visceral heterotaxy. (correct)

Lateralization.

It is narrow and pointed. Signup and view all the answers

Polysplenia. Signup and view all the answers

There is no real consensus on the distinction between polysplenia and one large spleen plus multiple small spleens. Signup and view all the answers

It indicates isomerism of the atrial situs. Signup and view all the answers

They lie apart with the aorta to the left. Signup and view all the answers

It is a rare exception to the rule of broncho-atrial concordance. Signup and view all the answers

Visualization of the tracheobronchial tree by plain chest radiography or bronchial tomography. Signup and view all the answers

Study Notes

Broad and blunt, extending from the superior vena cava to the inferior vena cava
Contains parallel trabeculations (musculi pectinati) that run around the atrio-ventricular junction and insert into the crista terminalis at right angles

Narrow and pointed, often resembling a crooked finger
Musculi pectinati are confined within the appendage, making the left atrial vestibule smooth

Presence of a morphologically left appendage on one side and a morphologically right appendage on the other constitutes lateralization
Can be seen in situs solitus or situs inversus
Isomerism occurs when there is duplication of morphologically right or left structures on each side of the body
Right isomerism is associated with asplenia, while left isomerism is usually accompanied by polysplenia

In right isomerism, both lungs tend to have three lobes and are fed by eparterial bronchi
In left isomerism, both lungs tend to be bilobed and have hyparterial bronchi

Atrial appendages provide the best guide to isomerism within the heart
Musculi pectinati encircling both atrio-ventricular junctions indicate right isomerism
Bilaterally smooth vestibules indicate left isomerism
A ratio between the lengths of the two main bronchi less than 1.6 indicates isomerism, while a ratio higher than 1.6 indicates lateralization
Cross-sectional echocardiographic scanning of the descending aorta and inferior caval vein can also accurately infer atrial arrangement