Fig. 3: Elongated cardiomyocytes form the inner atrial muscle structures.
From: Distinct mechanisms regulate ventricular and atrial chamber wall formation

a–c 3D surface rendering of a 14 dpf fixed atrium; outer layer myocardium shown in white and inner layer myocardium in cyan. a’–c’ 3D confocal image of the atrium from which the surface rendering was created; CM membranes shown in white for outer layer CMs and in cyan for inner layer CMs; all CM nuclei are shown in yellow.