Our bodies are a universe of 37.2 trillion cells operating in more or less perfect concert more or less all the time.
-- Narrator -- Bill Bryson (chapter 1)

Importance: This quote encapsulates Bryson's main thesis about the body: That it is a universe of its own. He notes the number of cells in our bodies, which is an astounding number, especially when one considers, as he points out in the quote, that all these cells must work together.

To all of them (microbes), you are not a person but a world -- a vast and jouncing wealth of marvelously rich ecosystems with the convenience of mobility thrown in, along with the very helpful habits of sneezing, petting animals, and not always washing quite as fastidiously as you really ought to.
-- Bill Bryson (chapter 3)

Importance: This quote attempts to flip readers' views of their bodies and help them see themselves the way microbes might. Bryson often uses this strategy in The Body: A...