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These are the first heart sound (S 1) and second heart sound (S 2), produced by the closing of the atrioventricular valves and semilunar valves, respectively. In addition to these normal sounds, a variety of other sounds may be present including heart murmurs , adventitious sounds , and gallop rhythms S 3 and S 4 .
Aristotle observed that the heart was the origin of the veins in the body, and concluded that the heart was the centre of the psycho-physiological system. He also stated that the existence of pneuma in the heart was to function as a messenger, traveling through blood vessels to produce sensation. Movement of body parts was thought to be ...
In a healthy heart all activities and rests during each individual cardiac cycle, or heartbeat, are initiated and orchestrated by signals of the heart's electrical conduction system, which is the "wiring" of the heart that carries electrical impulses throughout the body of cardiomyocytes, the specialized muscle cells of the heart.
The resting heart rate of a newborn can be 120 beats per minute (bpm) and this gradually decreases until maturity and then gradually increases again with age. The adult resting heart rate ranges from 60 to 100 bpm. Exercise and fitness levels, age and basal metabolic rate can all affect the heart rate. An athlete's heart rate can be lower than ...
Normal heart rate (classically 60 to 100 beats per minute for an adult). Regular rhythm, with less than 0.16-second variation in the shortest and longest durations between successive P waves; The sinus node should pace the heart – therefore, P waves must be round, all the same shape, and present before every QRS complex in a ratio of 1:1.
The heart is the first functional organ to develop and starts to beat and pump blood at about three weeks into embryogenesis. This early start is crucial for subsequent embryonic and prenatal development. The heart derives from splanchnopleuric mesenchyme in the neural plate which forms the cardiogenic region.
The heart is located in the middle of the abdomen with its tip slightly towards the left side of the abdomen. Disorders of the heart lead to heart disease and cardiovascular disease and can lead to a significant number of deaths: cardiovascular disease is the leading cause of death in the U.S. and caused 24.95% of total deaths in 2008. [19]
Only three women in Grammys history have taken home the award for Best Rap Album: Lauryn Hill, Cardi B, and—as of tonight—Doechii. The Alligator Bites Never Heal artist was visibly emotional ...