The Human Body: The Advantages of Specialization
Being multicellular has definite advantages. The form and size of the human body, our ability to run and swim, the levels of thought and sensation that we experience…all are a consequence of having a body that is composed of many cells. Because we are composed of trillions of individual cells, our cells have the freedom to specialize on their own individual tasks (Fig. 6.1). Cells in our skin specialize in protection by building tough networks of insulating proteins. Cells in our digestive tract are experts in absorption and metabolism of food and nutrients, feeding the rest of the body. Cells in our muscles specialize in generating force, and bone cells entomb themselves in mineral crystals, building a skeleton that articulates this force. A few remarkable cells in the gonads specialize in reproduction. They guard the information and resources that are needed, with the help of a matched cell from the opposite sex, to build an entire new human body. Perhaps most amazing of all, cells in our brain specialize in processing chemical and electrical signals, giving rise to our rich inner world of mind.