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An artificial cardiac pacemaker (or artificial pacemaker, so as not to be confused with the natural cardiac pacemaker) or just pacemaker is an implanted medical device that generates electrical impulses delivered by electrodes to the chambers of the heart either the upper atria, or lower ventricles to cause the targeted chambers to contract and ...
In a healthy heart, the SA node continuously produces action potentials, setting the rhythm of the heart (sinus rhythm), and so is known as the heart's natural pacemaker. The rate of action potentials produced (and therefore the heart rate ) is influenced by the nerves that supply it.
Cardiac physiology or heart function is the study of healthy, unimpaired function of the heart: involving blood flow; myocardium structure; the electrical conduction system of the heart; the cardiac cycle and cardiac output and how these interact and depend on one another.
A slow heart rate of 60 or less beats per minute is defined as bradycardia. A fast heart rate of more than 100 beats per minute is defined as tachycardia. An arrhythmia is defined as one that is not physiological such as the lowered heart rate that a trained athlete may naturally have developed; the resting heart rates may be less than 60 bpm.
The coronary sinus receives blood mainly from the small, middle, great, [2] and oblique cardiac veins. It also receives blood from the left marginal vein and the left posterior ventricular vein. [citation needed] Great cardiac vein (run upwards in the anterior interventricular sulcus to the left atrioventricular groove to form the coronary ...
Each pulse causes the targeted chamber(s) to contract and pump blood, [3] thus regulating the function of the electrical conduction system of the heart. The primary purpose of a pacemaker is to maintain an even heart rate, either because the heart's natural cardiac pacemaker provides an inadequate or irregular heartbeat, or because there is a ...
Cardiovascular physiology is the study of the cardiovascular system, specifically addressing the physiology of the heart ("cardio") and blood vessels ("vascular").. These subjects are sometimes addressed separately, under the names cardiac physiology and circulatory physiology.
The great cardiac vein (left coronary vein) is a vein of the heart. It begins at the apex of the heart and ascends along the anterior interventricular sulcus [ 1 ] before joining the oblique vein of the left atrium to form the coronary sinus [ 2 ] upon the posterior surface of the heart.