Across
- 3. normally produced both by the adrenal glands and by a small number of neurons in the medulla oblongata.
- 4. a fist- sized organ that pumps blood throughout your body.
- 7. a thin two- layered fluid filled sac that covers the outer surface of the heart.
- 10. a small branch of an artery leading into capillaries.
- 11. Pressure, force that blood exerts on blood vessels. it rises and fall as the heart as the heart contracts and relaxes.
Down
- 1. the main artery that carries blood away form your heart to the rest of your body.
- 2. the phase of the heartbeat when the heart muscle relaxes and allows the chambers to fill with blood.
- 5. large blood vessels that carry blood toward the heart.
- 6. large thick-walled muscular vessel that carries blood away from the heart.
- 8. microscopic blood vessels with walls only one cell thick that allows for diffusion of gases and nutrients between the blood and surrounding tissues.
- 9. one of the heart's four chambers. it is in the bottom left portion of the heart. which Ventricle is this?