This introductory book for undergraduate students poses a question: What is bioengineering all about? After offering a reference frame and defining the objectives (chapter 1), "physiology" (chapter 2) is presented as a source material followed by "signals" (chapter 3) and "signal pick up" (chapter 4). Chapter 5 deals with the biological amplifier. Reading the signal and the need for mathematical models are the subject matter, respectively, of chapters 6 and 7; they only provide guidance. The last chapter tries to look ahead. Sometimes, the subject is treated in relative depth; at times, the visit is more superficial. Formation rather than information is favored. Historical shots supply background material and spicy insights. Style is light, sprinkled with a little humor. There are exercises which allow students to learn independently.