Images Dated 10th September 2003

BIO10742

Livingstone daisy or Ice plant (Dorotheanthus bellidiformis) flowers. Leaves are covered by clear bobbles that look like beads of ice, South Africa

© BIOSPHOTO/AUSCAPE All rights reserved

Coloured SEM of a blood clot in coronary artery

Thrombus. Coloured Scanning Electron Micrograph (SEM) of a thrombus (blood clot) inside a coronary artery of the human heart. The artery has been cross-sectioned, showing its wall (brown) and inner lumen (blue). A blood clot (red) is seen, blocking about 30% of the width of the artery. Two coronary arteries supply blood to the heart muscle. A clot in one of these arteries (called coronary thrombosis) is most commonly caused by the build-up of atheroma (fatty deposits) on the artery walls. Impeded blood flow from a clot starves the heart of oxygen and may lead to heart attack. Magnification: x30 at 6x7cm size. x40 at 4x5ins

© PROFESSOR P.M. MOTTA, G. MACCHIARELLI, S.A NOTTOLA/SCIENCE PHOTO LIBRARY

False-colour SEM of the aortic valve

Heart valve. False-colour scanning electron micrograph of the aortic valve (bottom centre). It lies between the left ventricle of the heart and the aortic arch and consists of a fibrous annulus (ring) which has three semilunar pockets attached to it. In the diastole phase the aortic valve is closed maintaining the aortic column of blood at a roughly constant pressure. In ventricular sistole the blood pressure in the left ventricle rises rapidly and when it is higher than the aortic pressure the aortic valve opens. At top left some papillary muscles of the right atrium are visible. Magnification: x93 at 6x7cm size. x150 at 4x5 inch

© PROFF. P. MOTTA/G. MACCHIARELLI/UNIVERSITY LA SAPIENZA , ROME/SCIENCE PHOTO LIBRARY