Search results
Results From The WOW.Com Content Network
The cardiac cycle is the performance of the human heart from the beginning of one heartbeat to the beginning of the next. [1] It consists of two periods: one during which the heart muscle relaxes and refills with blood, called diastole, following a period of robust contraction and pumping of blood, called systole. [1]
Cardiac physiology. 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.
Systole (/ ˈsɪstəli / SIST-ə-lee) is the part of the cardiac cycle during which some chambers of the heart contract after refilling with blood. [1] Its contrasting phase is diastole, the relaxed phase of the cardiac cycle when the chambers of the heart are refilling with blood.
A Wiggers diagram, named after its developer, Carl Wiggers, is a unique diagram that has been used in teaching cardiac physiology for more than a century. [1][2] In the Wiggers diagram, the X-axis is used to plot time subdivided into the cardiac phases, while the Y-axis typically contains the following on a single grid: The Wiggers diagram ...
In cardiac physiology, isometric contraction is an event occurring in early systole during which the ventricles contract with no corresponding volume change (isometrically). This short-lasting portion of the cardiac cycle takes place while all heart valves are closed. The inverse operation is isovolumetric relaxation diastole with all valves ...
Diastole (/ daɪˈæstəli / dy-AST-ə-lee) is the relaxed phase of the cardiac cycle when the chambers of the heart are refilling with blood. The contrasting phase is systole when the heart chambers are contracting. Atrial diastole is the relaxing of the atria, and ventricular diastole the relaxing of the ventricles.
Cardiac cells have two refractory periods, the first from the beginning of phase 0 until part way through phase 3; this is known as the absolute refractory period during which it is impossible for the cell to produce another action potential. This is immediately followed, until the end of phase 3, by a relative refractory period, during which a ...
A pressure–volume diagram (or PV diagram, or volume–pressure loop) [1] is used to describe corresponding changes in volume and pressure in a system. They are commonly used in thermodynamics, cardiovascular physiology, and respiratory physiology. PV diagrams, originally called indicator diagrams, were developed in the 18th century as tools ...