Distribution of Elastic Fibres in the Human Abdominal Linea Alba

Abstract

The linea alba (LA) supports biomechanical stress generated by intra-abdominal pressure. It is believed to contain connective tissue fibres, which provide tensile strength and pliancy. Previous studies have dwelt on collagen fibres with scarce reports on elastic fibres. Biomechanical studies have shown that the LA has elastic properties, which display regional  variation. This study describes the pattern of distribution of elastic fibres in the LA in 18 young adults. Five millimetre transverse sections were taken from the supraumbilical, umbilical and infraumbilical regions of the LA. These sections were processed for paraffin embedding, sectioned, then stained with Weigert’s resorcin and fuchsin and counter-stained with Van Gieson in order to visualize elastic and collagen fibres. Under light  microscopy, a substantial amount of elastic fibres is present in the LA with higher amounts in the anterior, caudal and lateral parts. The elastic fibres are longitudinally and obliquely disposed in the entire length of the LA. These elastic fibres are more abundant in the anterior lamina, in the lateral and caudal parts of the LA. The elastic fibres demonstrated probably confer reversible pliability to the LA. The regional variations in their  distribution may reflect differences in function of the parts of the LA: namely an upper respiratory and a lower visceral support.

Key Words: Linea alba, collagen fibres, elastic fibres, regional variation, anterior abdominal wall