Paul Harding, age 7, of san Diego, Calif., for his question:
What is histology?
Young students like big fancy words like supercalifragilisticexpialidocious. They also like words that most people do not use very often, such as histology. And to find the meaning of histology, our young student will meet with seVeral other rare and fine sounding words.
Histology rhymes with biology, and such words are the names of sciences. Biology is the science of living things, and a biologist may study plants or animals. He cannot study everything about every living thing in the world beCause there are too many of them, so he studies just a few things in detail. He may study botany, the science of plants. Many biologists specialize in zoology and study the world's wild animals.
Biologists began to study living things more than 2,000 years ago. But for ages they did not know that all plants and animals are mad£ of tiny living cells. These small units of living material are too tiny for human eyes to see. Your body is made from billions of these wondrous cells, while a microbes made from only one living cell. Early biologists never guessed that the world is populated with swarms of one celled plants and animals.
This part of biology had to wait until the microscope was invented about 400 years ago. The microscope is fitted with lenses to make small things look bigger, and the biologists used it to look for small details in their plants and animals. They soon found a number of tiny one celled plants called bacteria, and then some biologists began to specialize in bacteriology.
Other biologists began to study the fine details in bones and fleshy muscles, in leaves and woody tree trunks. They soon discovered that all this material is made from little cells. some biologists made detailed studies of how these living cells are arranged. They noticed how the cells are fitted together like webs and fabric. They called these fabrics of interlocking cells living tissue, and they found a name for their special branch of biology.
They borrowed the Greek word histos, which means a web, and used it to name the science of histology. Histologists study tissues of cells in both plants and animals. They know how teams of cells in our bodies work together to use food and produce energy, to grow and mend themselves.
The curious biologists were not satisfied with histology. They wanted to know more about how cells and teams of cells do all their wondrous work. They wanted to know how Cells use atoms and molecules of food, air and water. so they invented finer microscopes and learned about the chemistry of atoms. Many histologists and bacteriologists and microbiologists then became molecular biologists. And molecular biologists probe the very deepest secrets of cells and living tissue.