Across
- 4. Control heart rate by decreasing the heart beat.
- 5. neurotransmitter caused the heart beat decrease.
- 8. Act as protection of the heart and a lubrication to reduce friction between heart and surrounding structures
- 11. Inner layer of heart wall
- 12. upper chamber of the heart
Down
- 1. The heart has _____ chambers
- 2. sarah felt scared as she was threatened by the robber caused the ________ is released
- 3. Heart sounds are produced by the closing of the ______
- 6. To check heart's rhythm and electrical activity
- 7. Valve between the left ventricle and the aorta
- 9. Separate the right and the left side of the heart.
- 10. Right atrium receives __________ blood from the body