INTRODUCTORY REMARKS

It May be appropriate to a pediatric audience in a consideration of cellular structure and function to quote from an old nursery rhyme, familiar to most of us: Little girls are made of Sugar and spice and all that's nice— And little boys are made of Frogs and snails and puppy dog tails. Actually, we know that this is not the case, and that little boys and girls are made of cells—millions and millions of them. The human infant at birth is said to contain 10 trillion cells. It, therefore, seems reasonable that prior to a discussion of the numerous diseases which affect children ("bundles of cells"), their nutritional and other requirements, that we consider a basic unit of life—the cell. To the medical student of a quarter of a century ago, and for many years thereafter, the study of the cell held little fascination. Structurally, it was recognized that there was a cell membrane which enclosed a cytoplasmic mass and nucleus, and there were structural substances such as mitochondria within the cytoplasm. The cell as a "chemical factory" was known to biologists, biochemists and geneticists for many years, but this knowledge had very limited influence on medical practice. Physicians thought more in terms of organ function, rather than cell function. This attitude has undergone striking change with the widespread therapeutic usage of vitamins, hormones (particularly the steroid hormones), antibiotics and antimetabolites in clinical medicine. With the recognition of the unity of nature, the biologic similarity between human cells and single-cell organisms and the biologic information gained in the study of single-cell organisms, there has been kindled a widespread and excited inquiry into the functions of the cells of humans.