Catatan

Near the end of one of the most famous speeches in American history, Abraham
Lincoln made reference to “government of the people, by the people, for the
people” [5]. In a similar vein, a text about physics and the human body could cover
“physics of the body, by the body, and for the body,” but perhaps that would be too
broad. Our main focus in this second edition is still the physics of the body, namely
the physics of physiology, and the text is again largely organized by topics in
physiology. There is still a strong emphasis on modeling physiology. As noted in
the excellent book by Rideout [7], general modeling in physiology includes that of
momentum (such as blood flow), mass (oxygen, carbon dioxide, and so on in the
blood), energy (heat flow), and information (signals in nerves, hormones in the
bloodstream) [7]. Models coupling multiple systems are also important. (After all,
we are all strongly coupled multiple physiological systems, which are, of course,
ultimately determined by physics.) We will still confine ourselves to the more
physical and less chemical aspects of physiology modeling; chemical modeling is
addressed well elsewhere [1, 2, 3, 4, 6, 7]. Within our focus of “physics of the
body,” we have enhanced the discussion of the physics of disease, aging, motion,

and the structure and function of muscles, and now explore how balance, meta-
bolism, and the circulatory system change during pregnancy and birth. The physics

of the cross-cutting lifecycle events of pregnancy, injuries, diseases and disorders,

aging, and dying transcend the topics of any single chapter. They are now over-
viewed in the new Appendix F; this appendix also describes how to locate dis-
cussions of these topics within the main text.