Knee replacement, X-ray
Knee replacement. Coloured X-ray of theprosthetic knee (white), seen in profile, of apatient with osteoarthritis. The implant attachesto the leg bones (blue/white), and has a flexiblejoint that can hinge like the old joint. Theimplant is attached to the top of the tibia (shinbone, lower frame) and to the bottom of the femur(thigh bone, upper frame). The other lower legbone (fibula) is also seen (right of tibia), as isthe patella (kneecap, left of implant). Theimplant replaced the old joint that had lost itscartilage due to osteoarthritis. Healthy cartilagereduces friction between the bones, and itsprogressive loss causes joint pain and immobility.
© Zephyr/Science Photo Library
Starfish and abalone, X-ray
Starfish and abalone. Coloured X-ray of a starfish (class Asteroidea) and an abalone (Haliotis sp.). A starfish typically has 5 arms radiating outward from a central disc. Tube feet (not seen) located on the undersides of the arms are used for movement. A starfish does not have a brain. Instead, coordination is controlled by one or more rings of centrally-located nerves. An abalone is a mollusc, related to limpets and snails. Its flat shell contains a row of holes, through which inhaled sea water is expelled after respiration is complete. Several species of abalone are edible and are an important food source.
© D. ROBERTS/SCIENCE PHOTO LIBRARY
Lung bronchogram, coloured X-ray
Healthy lung. Coloured bronchogram x-ray of a side (lateral) view of a healthy human lung. The vertebrae of the spinal column are seen at left. At lower right, the bottom two ribs of the rib cage are visible as diagonal bands. From the trachea (not seen) air passes into each lung via a bronchus. This tube branches into many bronchioles (centre, red), to deliver air to every part of the lung. The bronchioles divide to form tiny air sacs called alveoli (not seen) where gaseous exchange occurs. Bronchography renders the airways visible on X-ray film by prior injection of a radio-opaque contrast medium into the windpipe.
© PASIEKA/SCIENCE PHOTO LIBRARY