A philosophy professor I had in college once commented on how the dominant technology of the day becomes the dominant image we have of our mind and rationality and the workings of our bodies. If gears and pulleys run our machines, we tend to think of ourselves in terms of gears and pulleys.
If planting, harvest, and weather make up our way of life, elements like air and fire and water will suffice to explain the mystery of the human body. If computers or chemicals dominate our work and study, we frame our thinking about our bodies in terms of chemistry and computing. We are so sure that this is indeed the way our bodies work, and then the next age giggles at our simplicity and replaces the image.