September Gallery

Ebola virus

Ebola virus. Coloured transmission electron micro- graph of a single Ebola virus, the cause of Ebola fever. It is one of the group of filoviruses, so- called for its thin and long shape. Here the viral filament is seen looping in on itself. A number of major outbreaks of this severe, frequently fatal viral haemorrhagic fever have occurred in equatorial Africa since 1976, one in Zaire in 1995. The virus appears similar to, but is antigenically distinct from the Marburg virus which causes green monkey disease. The illnesses from both Ebola and Marburg viruses are similar, with fever, skin rash, and haemorrhage. Death may be rapid. Magnification: x19, 000 at 6x7cm size. x66, 500 at 8x10". This is the "reston" strain of Ebola, from Philadelphia, USA

© Barry Dowsett/Science Photo Library

Illustration of lung bronchioles and alveoli

Illustration of lung bronchioles and alveoli. The lung consists of many branched air passages called bronchioles (upper left), which end in groups of tiny balloon-like sacs called alveoli. It is in each alveolus that gases are exchanged during re- spiration. The bronchiole walls are lined spirally with smooth muscle (here, coloured orange). The alveolar sacs are thin-walled and supplied with a capillary network of blood vessels. Pulmonary veins (blue) bring deoxygenated blood to the lungs which is oxygenated by gas exchange across the alveolar walls (see lower left). Arteries (red) transport this oxygenated blood to the body. There are about 300 million alveoli in a human lung

© John Bavosi/Science Photo Library