Across
- 6. The circulation of blood from the heart to the lungs for oxygenation and back to the heart.
- 8. Extremely narrow, microscopic blood vessel. The presence of blood in capillaries produces the pink color of skin.
- 9. A chemical substance formed in some organ of the body, secreted directly into the blood, and carried to another organ or tissue, where it produces a specific effect.
- 11. The windpipe; in mammals, it extends from the throat to the bronchi.
- 12. A pair of ductless glands, each located on or adjacent to a kidney, which secretes adrenaline and cortin.
- 15. The main vessel that carries blood to all bodily organs except the lungs.
- 16. Either of two spongy, saclike respiratory organs in most vertebrates, occupying the chest cavity together with the heart or functioning to remove carbon dioxide from the blood and provide it with oxygen.
- 17. A blood vessel that functions in carrying blood from the heart.
- 18. The number of times the heart beats in a minute.
- 19. The act of bringing air into the lungs through the contraction of the diaphragm.
Down
- 1. One of many subdivisions of the bronchial tubes within a lung; a small branch of the bronchus.
- 2. The large veins that carry blood into the right atrium of the heart.
- 3. (bronchi) A major airway of the respiratory system.
- 4. One of the two pumping chambers of the heart.
- 5. The expansion and contraction of an artery associated with each heartbeat.
- 7. The organ of the body that circulates the blood by its rhythmical contractions.
- 10. The oxidation of organic compounds that occurs within cells, producing energy for cellular processes.
- 13. The layer or sheet of muscle and connective tissue that forms the wall between the thoracic and abdominal cavities of mammals and aids in the process of breathing.
- 14. The upper portion of the trachea.