| A | B |
|---|
| Other name for circulatory system: | cardiovascular system |
| Muscular hallow organ that pumps: | heart |
| What is the approximate size of the heart: | fist-size |
| How many layers of tissue form the heart? | Three: endocardium, myocardium, pericardium |
| Tissue that lines inside of heart: | endocardium |
| Thick middle, muscular layer of heart tissue: | myocardium |
| Double membrane that covers outside of heart | pericardium |
| Inflammation of heart lining: | endocarditis |
| Two upper chambers of heart: | atria (singular: atrium) |
| Bottom chambers of heart: | ventricles |
| Heart chamber that 1st receives returning, low-oxygenated blood: | right atrium |
| Chamber that 1st receives high oxygenated blood: | left atrium |
| Valve that separates right atrium from right ventricle: | tricuspid valve |
| Valve located between right ventricle & pulmonary artery: | pulmonary valve |
| Valve between left atrium & left ventricle: | mitral valve |
| Valve between left ventricle & aorta: | aortic valve |
| Cycle at which heart is at rest: | diastole |
| Period when heart is in ventriclular contraction: | systole |
| Group of nerve cells which are located in right atrium & initiate cyclic contractions: | pacemaker |
| Name of heart's pacemaker: | sinoatrial node (SA node) |
| Nerve fibers in the heart's septum: | Bundle of His (hiss) |
| Network of nerve fibers throughout ventricles that stimulates ventricular contraction: | Purkinje fibers |
| Record of measurement of electrical impulses of the heart: | EKG (electrocardiogram) |
| Electrical wave during contraction of atria: | P wave |
| Electrical component that shows excitation (contraction) of ventricles: | QRS complex |
| Electrical wave that is recovery (relaxation) phase of ventricles: | T wave |
| Blood vessels that carry blood away from heart: | arteries |
| Blood vessels that carry blood back to heart: | veins |
| Smallest vessels that connect arteries to veins: | capillaries |
| Thickness of capillary walls: | one epithelial cell |
| Smallest branches of veins that connect to capillaries: | venules (VEN-youls) |
| Smallest branches of arteries that connect to capillaries: | arterioles (ar-te-rE-olz) |
| Two largest veins in the body: | superior & inferior vena cavae |
| Quarts of blood in average adult: | 4 to 6 quarts |
| What gas does blood transport from lungs? | oxygen |
| What gas does blood transport from body cells & expel from the lungs? | carbon dioxide |
