Outflow Tract Cushion

The outflow tract cushion tissue arises from the cardiac neural crest, from the endocardium and from pharynx-derived mesenchyme, and plays a critical role in proper separation of the aorta from the pulmonary artery. This type of cushion tissue contains both truncal and distal cushions. The truncal cushion tissues are further remodeled to form the aortic and pulmonary semilunar valves.