infundibulum (right ventricle, anatomy)

Last reviewed 01/2018

The outflow tract of the right ventricle of the heart is derived from the bulbus cordis of the embryo. It is characterised by a relatively smooth surface in comparison to the inflow tract - there are no papillary muscles nor trabeculae carneae. It passes superiorly, posteriorly and to the left to reach the atrioventricular orifice and the pulmonary valve. With closer approximation to the atrioventricular orifice, the muscle within the wall of the outflow tract is replaced by fibrous and elastic tissue - it merges with the fibrous annulus of the pulmonary valve.

Also termed the infundibulum due to its funnel-like shape, the outflow tract has the following relations:

• inferolateral: supraventricular crest
• inferior: septomarginal trabecula
• posterior: root of the aorta
• superior: pulmonary trunk