Heart Sounds and the Cardiac Cycle

2. Although nerves aren’t responsible for cardiac contracts, innervation by the parasympathetic and sympathetic nerves can affect cardiac ________.
3. Blood traveling through the atrial chamber and leaving the ventricles moves from low to high _________.
5. During which phase of the cardiac cycle is blood pumped out of the heart?
7. Which arteries are responsible for supplying blood to the heart muscle?
10. The second “lub” heart sound is caused by closure of the aortic and ______ valves.
12. When the lungs are filling with air the ventricles are ______.
13. The process of blood flowing from the atria, a place of high pressure, to the ventricles, a place of low pressure, without muscle contraction is called ______ filling.
14. Which heart cells create an electrical signal that ensures heart contraction?
15. The _____ valve separates the left ventricle and the aorta.
16. This diagram represents the relationship between volume and pressure in the atria, ventricles, and aorta.
18. During the _______ phase of the cardiac cycle, ventricular pressure rises above aortic pressure to open the aortic valve.
19. The first “lub” heart sound is caused by closure of the ______ and tricuspid valves.

1. During which phase of the cardiac cycle is it sometimes possible to hear a third “lub,” caused by a rapid filling of the ventricles?
4. On an ECG reading, the T wave is produced by ventricular ________.
6. When blood leaves the heart to travel though the rest of the body it is _______.
8. On an ECG reading, the P wave is produced by atrial ______.
9. When open, which valve allows blood to flow from the atria to the ventricles?
11. Blood flows through the heart in an ______ manner.
17. The cells at the _______ node as the heart’s pacemaker.
20. During what phase of ventricular contraction is the pressure in the left ventricle lower than the pressure in the aorta?