Cardiovascular/Heart Vocabulary
Ventricular Septal Defect
A heart defect due to an abnormal connection between the lower chambers of the heart (ventricles)
Diastole
Diastole is the part of the cardiac cycle when the heart refills with blood following systole (contraction). Ventricular diastole is the period during which the ventricles are filling and relaxing, while atrial diastole is the period during which the atria are relaxing.
Purkinje Fibers
Purkinje fibers are a unique cardiac end-organ. Further histologic examination reveals that these fibers are split in atria and ventricles walls. The electrical origin of atrial Purkinje fibers arrives from the sinoatrial node.
Systole
Systole is the contraction phase of the cardiac cycle (contrast with diastole) that results in the ejection of blood into an adjacent chamber or vessel. Electrical systole can be recorded on an electrocardiogram (ECG) and precedes mechanical systole (the actual contraction).
S2 (second heart sound)
The "Dub" results from aortic and pulmonic valve closure. It is a sharper, louder sound than S1, and occurs at the end of ventricular systole.
S1 (first heart sound)
The "lub" is the first heart sound, commonly termed S1, and is caused by turbulence caused by the closure of mitral and tricuspid valves at the start of systole.
Atrioventricular node (AV Node)
The AV node is an area of specialized tissue between the atria and the ventricles of the heart, specifically in the posterior inferior region of the inreratrial septum near the opening of the coronary sinus, which conducts the normal electrical impulse from the atria to the ventricles.
Sinoatrial node (SA Node)
The SA node is the heart's natural pacemaker. The SA node consists of a cluster of cells that are situated in the upper part of the wall of the right atrium (the right upper chamber of the heart). The electrical impulses are generated there. The SA node is also called the sinus node.
Bundle of His
The bundle of His is a collection of heart muscle cells specialized for electrical conduction that transmits the electrical impulses from the AV node (located between the atria and the ventricles) to the point of the apex of the fascicular branches via the bundle branches.
chordae tendonae
The chordae tendineae are strong, fibrous strings attached to the leaflets (or cusps) of the heart on the ventricular side; i.e., the lower chamber. These strings originate from small mounds of muscle tissue, the papillary muscles, which project inward from the walls of the ventricle.
Endocardium
The endocardium is the innermost layer of tissue that lines the chambers of the heart. Its cells are embryologically and biologically similar to the endothelial cells that line blood vessels. The endocardium also provides protection to the valves and heart chambers.
interventricular septum
The interventricular septum (IVS), (or ventricular septum, or during development septum inferius), is the stout wall separating the lower chambers (the ventricles) of the heart from one another.
Myocardium
The myocardium is the muscular wall of the heart, or the heart muscle. It contracts to pump blood out of the heart and then relaxes as the heart refills with returning blood. The myocardium's smooth outer membrane is called the epicardium. Its inner lining is called the endocardium.
papillary muscles
The papillary muscles are muscles located in the ventricles of the heart. They attach to the cusps of the atrioventricular valves (also known as the mitral and tricuspid valves) via the chordae tendineae and contract to prevent inversion or prolapse of these valves on systole (or ventricular contraction).
atrioventricular valves
The two atrioventricular (AV) valves, the mitral valve (bicuspid valve), and the tricuspid valve, which are between the upper atria and the lower ventricles. The two semilunar (SL) valves, the aortic valve and the pulmonary valve, which are in the arteries leaving the heart.
Pericardium (visceral and parietal)
visceral pericardium: lines heart parietal pericardium: surrounds the visceral pericardium
