CARDIAC MUSCLE

1. The heart acts as a ________ to propel blood.
4. Cardiac muscle fibers are ________ than skeletal muscle fibers.
7. Cardiac muscle fibers also possess many mitochondria and _______.
8. Pacemaker cells are ________ to other cardiac muscle cells, allowing them to pass along signals.
11. Cardiac muscle tissue is one of the three types of _______ tissue.
12. Exercise can __________ your cardiac muscle.
14. Pacemaker cells control the ________ of your heart.
17. cardiac muscle has __________.
18. ________ muscle is found in the heart wall.
20. Cardiac cells have only a _________ nucleus.

2. When a cardiac muscle cell contracts, the ________ filament pulls the actin filaments toward each other.
3. _________ of cardiac muscle is pumping blood.
4. Your nervous system sends _________ to pacemaker cells that prompt them to either speed up or slow down your heart rate.
5. The heart acts as a pump to propel blood through the _______ vessels.
6. This through specialized cells called _______ cells.
7. Cardiac muscle cells also contain _________.
9. Involuntary heart ________ also a function of cardiac muscle.
10. Cardiac muscle cells appear striated or striped under a __________.
13. Cells joined end-to-end with ________ disk in between.
15. Cardiac cells have only a single _________.
16. Cardiac muscle also called heart muscle or ________.
19. The cell uses ATP to ______ this contraction.