Images Dated 10th March 2005

TEM of human white blood cell bearing HLA antigen

False-colour transmission electron micrograph (TEM) of a human white blood cell (bottom), showing presence of an HLA antigen (human leucocyte antigen), which appears as uneven red areas on exterior suface of the cell. The HLA antigens arise from a gene cluster on chromosome 6 in humans, which is referred to as the Major Histocompatability Complex (MHC). This title arose through studies on graft rejection in mice, where matched groups of antigens in donor & recipient animals markedly improved graft survival. In addition, it is now recognized that HLA antigens are involved in many other immunological processes. Magnification: X 8, 800 at 35mm size

© CNRI/SCIENCE PHOTO LIBRARY

Kidney tubules, SEM

Kidney tubules. Coloured scanning electron micrograph (SEM) of proximal convoluted tubules (dark brown) in the kidney. The proximal convoluted tubules function to reabsorb water, glucose and other small molecules from the filtrate, producing a concentrated urine. The tubules consist of a lumen (interior) lined with cuboidal epithelial cells. These cells are covered in many finger-like projections known as microvilli, which serve to increase the cell's surface area for reabsorption. The reabsorbed molecules move into the interstitial fluid of the kidney and are absorbed back into the blood. The liquid in the tubules passes to the bladder. Magnification: x420 when printed 10cm wide

© STEVE GSCHMEISSNER/SCIENCE PHOTO LIBRARY

Artwork of bones & ligaments in human knee joint

Knee joint. Illustration showing bones and tendons of the human knee (genual) joint. The knee is the largest joint in the human body. It forms the point of articulation between the upper leg bone (femur, at top) and the two bones of the lower limb (tibia at lower left, fibula at lower right). The articulation surface is formed from condyles (round bone ends) between the femur and tibia. These condyles are covered in cartilage (white) to prevent friction on movement. Ligaments (pink) fix this joint together: a fibular collateral ligament attaches the fibula to femur; cruciate ligaments attach tibia to femur between the condyles. The oval knee cap bone (patella) protects the joint

© JOHN BAVOSI/SCIENCE PHOTO LIBRARY