Heart minute volume at rest
At rest, the body’s need to be supplied with fresh blood and oxygen is lower than during exercise or sports. Overall, the heart beats more quietly at rest, the pulse is lower and the cardiac output is lower. Nevertheless, it is sufficient to supply the body with sufficient blood and oxygen.
Kidney and the cardiac output per minute
The kidney is provided with 20-25% of the heart minute volume. The kidney does not need so much of the oxygen contained in the blood, but filters the blood and absorbs or releases other components. In addition to washing the blood, the kidney is also responsible for excreting fluids in the form of urine.
It adapts this to the needs of the body. However, it is precisely for these two reasons that the kidney and heart influence each other. In the case of renal insufficiency, for example, less fluid is excreted and the preload and afterload are high. The heart therefore has to move more blood and the cardiac output increases, which in the long term leads to negative changes in the heart.
Control of the heart minute volume
Contractility, preload and afterload have an influence on the cardiac output per minute. Contractility describes the ability of the muscle to contract. Preload refers to the volume that is available in the chambers after the chambers have been completely filled.
Afterload, on the other hand, refers to the volume that remains in the heart after the heart muscle has contracted. The anatomical conditions of the heart are also important. These include the size of the heart chamber, the thickness of the heart wall and the function of the valves.
What influence does adrenaline have?
The release of adrenaline increases the cardiac output and thus the cardiac output per minute. Adrenaline acts on several pumping properties of the heart. Firstly, it accelerates the heart rate.
The heart’s own pacemaker cells become more active and send signals more frequently. In addition, the resulting signal is transmitted faster via the heart muscle. The force with which the heart contracts also increases.
In addition, the heart relaxes faster under the effect of adrenaline after contraction. This enables a faster sequence of beats. Due to the increased workload, the heart muscle requires a higher supply of nutrients and oxygen.
Therefore, the so-called coronary vessels dilate through adrenaline. They serve to supply the heart muscle.
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