Chapter 17 (Blood)
VERY Basic Animation of Blood Flow (it's a "silent" video): http://www.youtube.com/watch?v=nx-XRC_1n-Q
The Circulatory Rap Song (this is actually effective!) - this song perfectly captures, in a few minutes, what takes place when blood flows throughout the body: http://www.youtube.com/watch?v=q0s-1MC1hcE&feature=related
Good summary of this chapter: http://microvet.arizona.edu/courses/vsc401/pdf_files/BLOOD.PDF
Chapter 18 (Heart)
Quick summary: http://microvet.arizona.edu/courses/vsc401/pdf_files/HEART.PDF
Heart Anatomy (and function) Video: http://www.youtube.com/watch?v=S3vY5oyXmeI
Conduction System of Heart: http://www.youtube.com/watch?v=gvLe2hSi84s
Heart Valves: http://www.youtube.com/watch?v=4A6uPld3vZI
ECG: http://www.youtube.com/watch?v=nkKxSy9KFRU
Chapter 19 (Vessels)
Quick summary: http://microvet.arizona.edu/courses/vsc401/pdf_files/bloodVesselsHemo.PDF
Types of Blood Vessels: http://www.youtube.com/watch?v=CjNKbL_-cwA
Video PowerPoint Presentation of Vessels (Comprehensive Review): http://www.youtube.com/watch?v=UGWptlU3wVo
For chapter 19, know everything from the study guide (and nothing beyond it). The rest of the chapter will be covered in the next class period following your exam.
Anyway, I wish you good luck on your exams! Come to SI (before the test) if you need more visual representations in order to fully understand the concepts you are getting from lecture.