Images Dated 10th April 2003

Lung specimen diseased with emphysema

Emphysema. Specimen of sectioned human lung tissue diseased with pulmonary emphysema. At left is the affected lung area (black) with severe lung damage at far left. Normal lung tissue is at right. The scale reference is in centimetres. Emphysema is a disease in which the tiny air sacs (alveoli), the sites of gas exchange, become enlarged & the walls separating them damaged. As here, the walls may collapse. As a result carbon dioxide builds up in the blood and oxygen uptake is restricted, leading to breathlessness, wheezing, bluish skin and a chronic cough. Emphysema is usually caused by smoking. The disease is incurable, & if extensive areas of lung are damaged, death usually results

© DR. E. WALKER/SCIENCE PHOTO LIBRARY

False-colour SEM of the stapes in the middle ear

Middle ear. False-colour scanning electronmicrograph of the stapes, one of the threetiny bones found in the middle ear: the other twoare the malleus and the incus. They areinterconnected and link the tympanic membrane(eardrum) to the inner ear structure. The soundvibrations which strike the eardrum aretransmitted and amplified by the bones in themiddle ear to the complex system in the inner ear.Here, specialised ciliated neurone cells, convertthe mechanical energy of the sound waves intoelectrical impulses which are transmitted to thebrain for their analysis. Magnification: x15 at6x7cm size. x25 at 4x5"

© Prof.P.Motta/A.Caggiati/University la Sapienza , Rome/Science Photo Library