Development of the arterial roots and ventricular outflow tracts

J Anat. 2023 Nov 13. doi: 10.1111/joa.13973. Online ahead of print.ABSTRACTThe separation of the outflow tract of the developing heart into the systemic and pulmonary arterial channels remains controversial and poorly understood. The definitive outflow tracts have three components. The developing outflow tract, in contrast, has usually been described in two parts. When the tract has exclusively myocardial walls, such bipartite description is justified, with an obvious dogleg bend separating proximal and distal components. With the addition of non-myocardial walls distally, it becomes possible to recognise three parts. The middle part, which initially still has myocardial walls, contains within its lumen a pair of intercalated valvar swellings. The swellings interdigitate with the distal ends of major outflow cushions, formed by the remodelling of cardiac jelly, to form the primordiums of the arterial roots. The proximal parts of the major cushions, occupying the proximal part of the outflow tract, which also has myocardial walls, themselves fuse and muscularise. The myocardial shelf thus formed remodels to become the free-standing subpulmonary infundibulum. Details of all these processes are currently lacking. In this account, we describe the anatomical changes seen during the overall remodelling. Our interpretations are based on the interrogation of serially sectioned histological and high-resolution episcopic microscopy datasets prepared from developing human and mouse embr...

Source: Journal of Anatomy - November 14, 2023 Category: Anatomy Authors: Robert H Anderson Wouter H Lamers Jill P J M Hikspoors Timothy J Mohun Simon D Bamforth Bill Chaudhry Lorraine Eley Janet Kerwin Moira Crosier Deborah J Henderson Source Type: research