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Troponin I, cardiac muscle is a protein that in humans is encoded by the TNNI3 gene. [ 5 ] [ 6 ] It is a tissue-specific subtype of troponin I , which in turn is a part of the troponin complex . The TNNI3 gene encoding cardiac troponin I (cTnI) is located at 19q13.4 in the human chromosomal genome.
Cardiovascular fitness is a component of physical fitness, which refers to a person's ability to deliver oxygen to the working muscles, including the heart.Cardiovascular fitness is improved by sustained physical activity (see also Endurance Training) and is affected by many physiological parameters, including cardiac output (determined by heart rate multiplied by stroke volume), vascular ...
Cardiac muscle (also called heart muscle or myocardium) is one of three types of vertebrate muscle tissues, the others being skeletal muscle and smooth muscle. It is an involuntary, striated muscle that constitutes the main tissue of the wall of the heart .
The absolute refractory period for cardiac contractile muscle lasts approximately 200 ms, and the relative refractory period lasts approximately 50 ms, for a total of 250 ms. This extended period is critical, since the heart muscle must contract to pump blood effectively and the contraction must follow the electrical events.
Cardiac index is a critical parameter in evaluating cardiac performance and the adequacy of tissue perfusion. In healthy adults, the normal range of cardiac index is generally between 2.6 to 4.2 L/min/m². Values below this range may indicate hypoperfusion and are often seen in conditions such as heart failure, hypovolemia, and cardiogenic shock.
The cardiovascular system responds to changing demands on the body by adjusting cardiac output, blood flow, and blood pressure. Cardiac output is defined as the product of heart rate and stroke volume which represents the volume of blood being pumped by the heart each minute. Cardiac output increases during physical activity due to an increase ...
Increase the amount of calcium in the sarcoplasm. More calcium available for Troponin to use will increase the force developed. Decreasing contractility is done primarily by decreasing the influx of calcium or maintaining lower calcium levels in the cytosol of cardiac myocytes during an action potential.
The total length of muscle capillaries in a 70 kg human is estimated to be between 9,000 and 19,000 km. [21] ... Cardiac muscle – Muscular tissue of heart in ...