Images Dated 11th March 2003

Graphic of brain in head, with concentric circles

Human brain. Computer graphic of a side view of a male head with mesh contours, and a human brain superimposed. Concentric circles are emanating from the temporal region of the brain, in an abstract depiction of headache or dizziness. On the brain are seen surface folds and convolutions of the left cerebral hemisphere. The cerebrum is the largest most developed part of the brain, responsible for conscious thought, sensation and memory. Headache is a diffuse pain that may occur in different regions of the brain, including the temporal, frontal and occipital areas. Dizziness may be due to headache, or such factors as alcohol consumption or infectious disease

© PASIEKA/SCIENCE PHOTO LIBRARY

False-col TEM of polio virus particles

False-colour transmission electron micrograph (TEM) of numerous virions (virus particles) of the polio virus, the causative agent of poliomyelitis. Polioviruses belong to the enterovirus sub-group of the picornaviruses (small RNA viruses) & occur as 3 antigenically-distinct types; type 1 is responsible for the majority of polio epidemics. Infection occurs through the mouth, with the virus travelling via lymph nodes in the gut & upper respiratory tract to the central nervous system, where viral replication (especially in horn cells of spinal cord) may produce paralytic poliomyelitis (causing death or severe & permanent disability). Magnification: x29, 400 at 35mm size

© CNRI/SCIENCE PHOTO LIBRARY