hjärtverksamhet

Hjärtverksamhet refers to the functions and activities of the heart. The primary function of the heart is to pump blood throughout the body, supplying oxygen and nutrients to tissues and organs and removing waste products. This process is essential for life. The heart achieves this through a rhythmic cycle of contraction and relaxation, known as the cardiac cycle.

The cardiac cycle consists of two main phases: diastole and systole. During diastole, the heart muscle relaxes, allowing the chambers to fill with blood. During systole, the heart muscle contracts, ejecting blood into the arteries. This coordinated pumping action is controlled by the heart's electrical system, which generates impulses that trigger the contractions.

Key components of hjärtverksamhet include the heart rate, which is the number of times the heart beats per minute, and the stroke volume, which is the amount of blood pumped with each beat. The product of heart rate and stroke volume is cardiac output, representing the total volume of blood pumped by the heart per minute.

Factors influencing hjärtverksamhet include physical activity, emotional state, and underlying health conditions. For instance, exercise increases heart rate and stroke volume to meet the body's higher demand for oxygen. Conversely, stress or certain diseases can impair the heart's ability to function effectively. The efficient functioning of hjärtverksamhet is critical for maintaining overall bodily health and well-being.