Liver tissue. Transmission electron micrograph (TEM) of a section through the liver, showing part of a radial cord of hepatocyte liver cells (dark) and the vascular sinusoids (white). The hepatocyte cytoplasm notably contains mitochondria, rough endoplasmic reticulum and large amounts of glycogen. Sinusoids are a type of capillary, a small blood vessel. In the liver, this network of vessels infiltrates the tissue, supplying it with blood. Gases and nutrients are exchanged between the blood and surrounding tissue through the permeable walls of the capillaries. The gap between hepatocytes and the endothelium, known as the 'space of Disse', contains sparse collagen (reticular) fibres. Magnification: x7000, when printed 10 centimetres wide.