With this third edition of First Aid for the Basic Sciences: Organ Systems, we continue

our commitment to providing students with the most useful and up-to-date preparation

guides for the USMLE Step 1. For the past year, a team of authors and editors

have worked to update and further improve this third edition. This edition represents

a major revision in many ways.

■ Every page has been carefully reviewed and updated to reflect the most high-yield

material for the Step 1 exam.

■ New high-yield figures, tables, and mnemonics have been incorporated.

■ Margin elements, including flashcards, have been added to assist in optimizing the

studying process.

■ Hundreds of user comments and suggestions have been incorporated.

■ Emphasis is on deeper understanding and integration of critical concepts.

This book would not have been possible without the help of the hundreds of students

and faculty members who contributed their feedback and suggestions. We invite students

and faculty to please share their thoughts and ideas to help us improve First Aid

for the Basic Sciences: Organ Systems. (See How to Contribute, p. xiii.)