Most of us are familiar with the circulatory system, the internal 'plumbing' that directs blood around the body. But there's another set of 'pipes' that shift fluid around inside us, called the lymphatic system. This network of vessels takes excess fluid away from our tissues and plays a vital role in shuttling immune cells around. This confocal microscope image shows a tightly intertwined network of developing lymphatic vessels (stained pink) against a backdrop of blood vessels (stained blue). The green patches among the lymphatic vessels highlight a protein called reelin, which first came to light in brain development research. Scientists have discovered that reelin also plays an important role in lymphatic vessel growth, helping the muscle and lining cells communicate with each other to create correctly-shaped vessels.
Written by Kat Arney
BPoD stands for Biomedical Picture of the Day. Managed by the MRC London Institute of Medical Sciences the website aims to engage everyone, young and old, in the wonders of biomedicine. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.