Across
- 2. A rapid twitching of muscle fibers, as of the heart, that is caused by the abnormal discharge of electrical nerve impulses.
- 5. any one of the four veins that convey oxygen-rich blood from the lungs to the heart
- 8. the muscle tissue of the heart; adapted to continued rhythmic contraction
- 12. circulation that supplies blood to all the body except to the lungs.
- 13. Either of two arteries that originate in the aorta and supply blood to the muscular tissue of the heart.
- 14. A body cavity or chamber, especially either of the upper chambers of the heart that receives blood from the veins and forces it into a ventricle.
- 15. A type of blood circulation system in which the blood flows through the heart twice. In this type of circulation, the pulmonary circulation is separate from the systemic circulation.
- 16. circulation of blood between the heart and the lungs.
- 17. a network of fibres that carry the cardiac impulse from the atrioventricular node to the ventricles of the heart and causes them to contract
- 18. either of two heart valves through which blood flows from the atria to the ventricles; prevents return of blood to the atrium
- 22. oxygen has been removed from a sunstance.
- 23. oxygen has been infused with a substance.
- 24. The rhythmic contraction of the heart, especially of the ventricles, by which blood is driven through the aorta and pulmonary artery after each dilation or diastole.
Down
- 1. A small mass of specialized cardiac muscle fibers located in the posterior wall of the right atrium of the heart that acts as a pacemaker by generating at regular intervals the electric impulses of the heartbeat.
- 3. The rhythmic contraction (systole) and relaxation (diastole) of the chambers of the heart that corresponds to one heartbeat.
- 4. a tracing of the electric currents that initiate the heartbeat, used to diagnose possible heart disorders
- 6. To make smaller or narrower by binding or squeezing.
- 7. The normal rhythmically occurring relaxation and dilatation of the heart chambers, especially the ventricles, during which they fill with blood.
- 9. A small mass of specialized cardiac muscle fibers, located in the wall of the right atrium of the heart, that receives heartbeat impulses from the sinoatrial node and directs them to the walls of the ventricles.
- 10. A thin partition or membrane that divides two cavities or soft masses of tissue in an organism
- 11. Either of two valves, one located at the opening of the aorta and the other at the opening of the pulmonary artery, each consisting of three crescent-shaped cusps and serving to prevent blood from flowing back into the ventricles.
- 12. A type of blood circulation in which the system has only one circuit
- 19. a chamber of the heart that receives blood from an atrium and pumps it to the arteries
- 20. A tiny, thin-walled, capillary-rich sac in the lungs where the exchange of oxygen and carbon dioxide takes place.
- 21. Either of two large veins that drain blood from the upper body and from the lower body and empty into the right atrium of the heart.