Light microscopy of hemipenis from<i>Crotalus durissus terrificus.</i>

<p>A: Transversal cut of <i>musculus retractor penis magnus</i> showing muscles cells (MC) and the central sinusoid (CS). B: Detail of central sinusoid in a transversal cut of <i>musculus retractor penis magnus.</i> The central sinusoid (CS) is layered by smooth muscle cells (MC) and a endothelium, erythrocytes (arrow) are observed inside the sinusoid. C: Detail of <i>corpus cavernosum</i> internal, smooth muscle cells (SM); surrounding lacunar spaces (LA). D: Detail of a <i>trabecula</i>, the connective tissue (CT) are surrounded by smooth muscle cells (*) and endothelial cells (arrow) forming lacunar spaces (LA).