Images Dated 6th February 2003

Illustration of tissues of the pancreas

Illustration of tissues of the pancreas. Most of the pancreas is involved in secreting enzymes from clusters of gland cells (pancreatic acini), seen here coloured pink. However, the pancreas has two functions: secretion of digestive enzymes, and the production of hormones. Internal to the acini are yellow groups of cells named Islets of Langerhans. These are involved in the endocrine function of hormone production. Here, alpha cells (red) are involved in secreting glucagon. The numerous beta cells (yellow) secrete insulin. And delta cells (blue) secrete a hormone, somatostatin. The pancreas lies near the duodenum. A low production of insulin by the pancreas causes diabetes

© JOHN BAVOSI/SCIENCE PHOTO LIBRARY

Brain ventricles and other structures

Brain. Coloured composite 3-D magneticresonance imaging (MRI) scan of a human brain, seen from the front. The ventricles (purple)circulate the cerebrospinal fluid (CSF), whichcushions the brain. The two lateral ventricles lieeither side of the mid-line of the brain, one ineach cerebral hemisphere. They communicate withthe fourth ventricle (bottom centre). Beneath thelateral ventricles lie the sensory-processingthalami (yellow) and the hypothalamus (green, centre), which controls emotion and bodytemperature and releases chemicals that regulatehormone release from the pituitary gland (green, above fourth ventricle)

© Zephyr/Science Photo Library