Across
- 5. elastic artery
- 6. electrical junctions that are composed of connexion protein channels
- 13. anterior surface of the heart
- 14. thoracic compartment that occupies space in between the lungs
- 15. person that has a heart
- 18. returns oxygenated blood from lungs to left atrium
- 20. valves that are forced to open pressure is raised in the pulmonary trunk
- 21. valves that close when the blood pushing up is under the cusps
Down
- 1. forcibly fill the ventricles with blood
- 2. valve that is made up of two cusps or flaps
- 3. lubricate the wall of the heart so it can beat without friction
- 4. receives deoxygenated blood from body through veins
- 7. proteins span the distance between adjacent plasma membranes
- 8. valve that is composed of three cusps or flaps
- 9. located above the heart
- 10. four heart valves open and close in response to pressure in this
- 11. narrow space filled with pericardial fluid
- 12. thickest and consists of two tissue layers
- 16. the narrow end of the heart and directed downward and left
- 17. attached to blood vessels of the heart
- 19. secreted by the serous membranes