Glossary
Atrioventricular Valves
The valves between the right atrium and right vtricle (tricuspid) and the left atrium and left ventricle (mitral).
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Cardiac Output
The volume of blood expelled by the ventricles of the heart with each beat multiplied by the heart rate.
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Cardiovascular Shunt
Diversion of the blood flow through an anomalous opening from the left side of the heart to the right side or from the systemic to the pulmonary circulation (left-to-right), or from the right side to the left side or from the pulmonary to the systemic circulation (right-to-left).
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Chordae Tendineae
The strands of tendon that anchor the cusps of the mitral and tricuspid valves to the papillary muscles of the ventricles of the heart, preventing prolapse of the valves into the atria during ventricular contraction.
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Depolarisation
The process or act of neutralising polarity as in the decrease of membrane potential.
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Diastasis
The last stage of diastole in the heart, occurring just before contraction and during which little additional blood enters the ventricle.
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Diastole
The period between contractions of the atria or the ventricles during which blood enters the relaxed chambers from the systemic circulation and the lungs. Ventricular diastole begins with the onset of the second heart sound and ends with the first heart sound.
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Dicrotic Notch
A small downward deflection in the arterial pulse or pressure contour immediately following the closure of the semilunar valves and preceding the dicrotic wave, sometimes used as a marker for the end of systole or the ejection period
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Dicrotic Wave
In an arterial pulse recording, the portion of the descending limb following the aortic notch, including a second, smaller peak attributed to the reflected impulse of closure of the aortic valve.
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End-Diastolic Volume (EDV)
The volume of blood in each ventricle at the end of diastole, usually about 120–130 mL but sometimes reaching 200–250 mL in the normal heart
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End-Systolic Volume (ESV)
The volume of blood remaining in each ventricle at the end of systole, usually about 50–60 mL but sometimes as little as 10–30 mL in the normal heart.
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Lusitropy
A term used to describe myocardial relaxation. The increase in calcium uptake by cardiomyocytes leads to increased myocardial contractility (positive inotropic effect), but the myocardial relaxation, or lusitropy, decreases. Increased catecholamine levels promote positive lusitropy, enabling the...
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Murmur
A blowing or roaring heart sound heard through the wall of the chest; caused by blood flow through a defective valve.
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Myocyte
A single cell of muscle fiber, containing many myofibrils, the contractile unit of muscles. Muscle fibres are very long; a single fibre can reach a length of 30cm.
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QRS Complex
The portion of the electrocardiogram comprising the Q, R, and S waves, together representing ventricular depolarisation
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Repolarisation
The re-establishment of polarity, especially the return of cell membrane potential to resting potential after depolarisation
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Ryanodine Receptors
Ryanodine receptors (RyRs) form a class of intracellular calcium channels in various forms of excitable animal tissue like muscles and neurons. It is the major cellular mediator of calcium-induced calcium release (CICR) in animal cells.
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Sarcoplasmic Reticulum
A form of agranular reticulum in the sarcoplasm of striated muscle, comprising a system of smooth-surfaced tubules surrounding each myofibril.
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Semilunar Valves
One having semilunar cusps, i.e., the aortic and pulmonary valves; sometimes used to designate the semilunar cusps composing these valves.
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Stroke Volume
The volume of blood ejected from a ventricle at each beat of the heart, equal to the difference between the end-diastolic volume and the end-systolic volume.
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Systole
The rhythmic contraction of the heart, especially of the ventricles, by which blood is driven through the aorta and pulmonary artery after each dilation or diastole.
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T Wave
The deflection of the normal electrocardiogram following the QRS complex; it represents repolarisation of the ventricles
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All of the definitions here were taken from The Free Dictionary.