The purpose of this theme issue is to review the basic physiological, nutritional, and pathological facts pertaining to the liver. It is an educational tool through which university teachers and people in charge of training may enhance their teaching programs. The main liver diseases seen in young children and pregnant women in tropical regions is reviewed. The liver plays a key role in supplying nutrition to the body, and is capable of delivering the elements needed by the different body tissues in the form of simple, immediately utilizable nutrients, such as glucose, amino acid, fatty acids, and vitamins. The liver is the coordinating center for all the biochemical machinery of the body. Knowledge of the physiology of the liver is essential in order to understand the mechanisms at work in the different disorders, so that adequate, effective solutions may be chosen to repair or prevent them. The first part of this booklet describes the functions of the liver cells and their role in the major metabolic processes involving carbohydrates, protein, lipids and vitamins. The second part of the booklet discusses disturbances in the form of the main syndromes or groups of clinical signs evidenced during liver diseases, and more specifically jaundice, portal hypertension, and hepatic comas. Information on the five forms of viral hepatitis is provided. The booklet also discusses abscess, cirrhosis, impairment, and tumors of the liver, and provides information on hydatic cysts and hepatocarcinoma. A discussion of liver alignments in pregnant women, which includes benign hepatic jaundice, acute steatosis, and jaundice concomitant with pregnancy concludes the booklet. Contains 15 references. (MOK)