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Physiology 1
heart and lung function
Term | Definition |
---|---|
respiratory centre | area in the brain stem that controls breathing rate and depth |
pulmonary circulation | blood from the heart to the lungs and back to the heart with oxygen |
system circulation | oxygenated blood carried from the heart to body tissues and back to the heart. |
vasoconstriction | reducing flow of blood into capillaries |
vasodilation | increasing flow of blood into capillaries |
systolic pressure | pressure of heart contracting |
diastolic pressure | pressure of the relaxed heart |
venous return | mechanisms that assist the return of blood to the heart. |
skeletal muscle pump | muscle action squeezes veins and forces blood towards the heart |
respiratory pump | breathing movements force blood to flow towards the heart |
arterio-venous oxygen difference | amount of oxygen removed from the blood by the muscles |
SAN (sino-arterio node) | small mass of cardiac muscle that generates the heartbeat |
intrinsic | the idea that the heart generates it's own contraction from within itself |
myogenic | impulses generated without nervous stimulation |
AVN (atrio-ventricular node) | bundle of tissue that forms part of the conduction system |
bundle of His | specialised bundle of nerve tissue that forms part of the conduction system |
purkinje fibres | specialist nerve fibres found in the ventricles |
stroke volume | Volume of blood leaving the left ventricle per beat |
ejection fraction | proportion of blood in left ventricle pumped out each beat |
cardiac output | Stroke volume x heart rate |
Starling's law of the heart | the greater the venous return, the greater the strength of contraction |
chemoreceptors | group of cells sensitive to changes in blood acidity |
hypertrophy (athletes heart) | the increase in size of the heart that accompanies training |
bradycardia | the reduction in resting heart rate that accompanies training |