Striated muscle tissue. Coloured scanning electron micrograph (SEM) of a longitudinal section through striated muscle tissue, showing the muscle fibre cells and lateral streaking. Muscle fibres are muscle cells (myocytes) from cardiac and skeletal muscle. The muscle fibres are surrounded by cell tissue (beige) and collagen fibres (grey). At centre is a blood vessel containing red blood cells (erythrocytes, disks). Lateral streaking is a characteristic of skeletal musculature - in contrast to the smooth muscle found in places such as the bladder, blood vessels and intestines. Magnification: x1800, when printed 15 centimetres wide.