Across
- 2. a one-way, crescent-shaped, three-flap valve located between the right ventricle and the pulmonary artery
- 3. a one-way gate located on the right side of the heart between the top chamber and bottom chamber
- 5. a small, battery-powered device surgically implanted under the skin in the chest to treat slow or irregular heartbeats
- 8. a one-way, half-moon-shaped, three-leaflet structure located between the left ventricle and the aorta
- 11. the heart's natural pacemaker, a small cluster of specialized cells located in the top of the right atrium
- 13. one of the heart’s four chambers, located in the lower right section
- 14. a thin, two-layered, fluid-filled sac that surrounds and protects the heart
- 15. the upper right chamber of the heart that acts as a holding chamber for oxygen-poor blood returning from the body
- 17. a one-way, two-flap structure located between the heart's upper left chamber and lower left chamber
- 19. the thin, smooth, innermost layer of tissue that lines the four chambers and covers the valves of the heart
- 20. the body’s largest artery, acting as the main pipeline for oxygen-rich blood
- 21. the thick, muscular middle layer of the heart wall responsible for contracting to pump blood throughout the body
- 23. specialized, fast-conducting muscle cells located in the inner ventricular walls of the heart
Down
- 1. a medical emergency where the heart suddenly stops beating or malfunctions, causing it to stop pumping blood to the body and brain
- 4. the major blood vessel that carries oxygen-poor blood from the right side of the heart to the lungs for oxygenation
- 6. a small, specialized cluster of cells in the heart that acts as an "electrical relay station" or gatekeeper
- 7. one of the four chambers of the heart, located in the upper left section
- 9. the largest vein of the heart, acting as the main collector of deoxygenated blood from the myocardium
- 10. the body's largest vein, acting as the main "drainpipe" that returns oxygen-depleted blood from the body back to the heart
- 12. one of the heart’s four chambers, located in the lower left section
- 16. a specialized, 1.8 cm group of muscle fibers in the heart that carries electrical signals from the AV node to the ventricles
- 18. a thin wall, membrane, or partition that divides two cavities, spaces, or tissues within the body or in other structures
- 22. a collection of specialized heart muscle cells that transmit electrical impulses from the AV node to the ventricles