| A | B |
|---|
| aorta | The largest artery, it receives blood from the left ventricles and branches to all parts of the body. |
| aortic valve | The semilunar valve at the entrance to the aorta. |
| apex | The point of a cone-shaped structure. The apex of the heart is formed by the left ventricle. It is inferior and pointed toward the left. |
| artery | A vessel that carries blood away from the heart. Most arteries carry oxygenated blood. |
| arteriole | A small artery. |
| atrioventricular node | A small mass in the lower septum of the right atrium that passes impulses from the sinoatrial(SA) node toward the ventricles. |
| AV bundle | A band of fibers that transmits impulses from the atrioventricular(AV) node to the top of the interventricular septum. It divides into the right and left bundle branches which descend along the two sides of the septum. Also called bundle of His. |
| atrium | An entrance chamber. One of the two upper receiving chambers of the heart. |
| blood pressure | The force exerted by blood against the wall of a vessel. |
| capillary | One of the millions of microscopic blood vessels through which materials are exchanged between the blood and the tissues. |
| diastole | The relaxaton phase of the heart cycle. |
| endocardium | The thin membrane that lines the chambers of the heart and covers the valves. |
| epicardium | The thin outermost layer of the heart wall. |
| heart | The muscular organ with four chambers that contracts rhythmically to propel blood through vessels to all parts of the body. |
| heart sounds | Sounds produced as the heart functions. The two loudest sounds are produced by alternate closing of the valves and are designated S1 and S2 |
| mitral valve | The valve between the left atrium and left ventricle; the bicuspid valve. |
| myocardium | The thick middle layer of the heart wall composed of cardiac muscle. |
| pericardium | The fibrous sac that surrounds the heart. |
| pulmonary circuit | The system of vessels that carries blood from the right side of the heart to the lungs to be oxygenated and then back to the left side of the heart. |
| pulmonic valve | The semilunar valve at the entrance to the pulmonary artery. |
| Purkinje fibers | The terminal fibers of the conducting system of the heart. They carry impulses through the walls of the ventricles. |
| septum | A wall dividing two cavities, such as the chambers of the heart. |
| sinoatrial(SA) node | A small mass in the upper part of the right atrium that initiates the impulse for each heartbeat; the pacemaker. |
| sphygmomanometer | An instrument for detemining arterial blood pressure; blood pressure apparatus or cuff. |
| systemic circuit | The system of vessels that carries oxygenated blood from the left side of the heart to all tissues except the lungs and returns deoxygenated blood to the right side of the heart. |
| systole | The contraction phase of the heart cycle |
| tricuspid valve | The valve between the right atrium and the right ventricle. |
| valve | A structure that keeps fluid flowing in a forward direction |
| vein | A vessel that carries blood back to the heart. Most veins carry blood low in oxygen. |
| vena cava | One of the two veins(superior and inferior) that carry deoxygenated blood back to the right atrium of the heart. |
| ventricle | A small cavity. One of the two lower pumping chambers of the heart. |
| venule | A small vein |
| vessel | A tube or duct to transport fluid. |
| lymph | The thin plasma like fluid that drains from the tissues and is transported in lymphatic vessels. |
| lymph node | A small mass of lymphoid tissue along the path of a lymphatic vessel that filters lymph. |
| spleen | A large reddish-brown organ in the upper left region of the abdomem. It filters blood and destroys old red blood cells. |
| thymus gland | A gland in the upper part of the chest beneath the sternum. It functions in immunity. |
| tonsil | A small mass of lymphoid tissue in the throat that filters impurities. |
| apex beat | The pulsing of the heart that can be felt over the apex in the fifth left intercostal space, about 8-9 centimeters from the midline |
| cardiac output | the amount of blood pumped from the right or left ventricle per minute |
| ductus arteriosus | A vessel between the pulmonary artery and the aorta that bypasses the lungs in fetal circulation. Failure to close after birth is called patent ductus arteriosus |
| foramen ovale | An openng between the two atria that allows blood to bypass the lungs in fetal circulation. Failure to close after birth results in a septal defect. |
| Korotkoff's sounds | Arterial sounds heard with a stethoscope during determination of blood pressure with a cuff. |
| perfusion | The passage of fluid, such as blood, through an organ or tissue. |
| precordium | The anterior region over the heart and the lower part of the thorax. |
| pulse pressure | The difference between systolic and diastolic pressure |
| sinus rhythm | A normal heart rhythm originating from the sinoatrial (SA) node |
| stroke volume | The amount of blood ejected by the left ventricle with each beat. |
| Valsalva's maneuver | Bearing down, as in childbirth or defecation, by attempting to exhale forcefully with the nose and throat closed. This action has an effect on the cardiovascular system. |
