Atria: Difference between revisions
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The atria (singular [[Atrium|atrium]]) are the upper chambers in the [[Heart|heart]] that receive blood from large [[Vein|veins]] and deliver it to [[Ventricles|ventricles]]. They have thin walls compared to ventricles, as the [[Blood|blood]] is only moving a short distance down to the ventricles, therefore little [[Muscle|muscle]] is needed compared to ventricles which pump the blood over larger distances.<ref>Pocock G., Richards C. (2006) Human Physiology: The Basis of Medicine, 3rd Edition, Oxford University Press</ref> Atria are involved in the first stages of the [[Cardiovascular cycle|cardiovascular cycle]] mediated by the [[Sinoatrial Node|Sinoatrial Node]] ([[SAN|SAN]]). A wave of depolarization sweeps over the the atria causing them to contract, which forces blood from the atria into the ventricles. The SAN acts a pacemaker whereby it could generate [[Action potential|action potential to]] control heart rate<ref name="null">Quain, Jones. (1908) Quain's Elements of Anantomy, 4. London: Longmans, Green | The atria (singular [[Atrium|atrium]]) are the upper chambers in the [[Heart|heart]] that receive blood from large [[Vein|veins]] and deliver it to [[Ventricles|ventricles]]. They have thin walls compared to ventricles, as the [[Blood|blood]] is only moving a short distance down to the ventricles, therefore little [[Muscle|muscle]] is needed compared to ventricles which pump the blood over larger distances.<ref>Pocock G., Richards C. (2006) Human Physiology: The Basis of Medicine, 3rd Edition, Oxford University Press</ref> Atria are involved in the first stages of the [[Cardiovascular cycle|cardiovascular cycle]] mediated by the [[Sinoatrial Node|Sinoatrial Node]] ([[SAN|SAN]]). A wave of depolarization sweeps over the the atria causing them to contract, which forces blood from the atria into the ventricles. The SAN acts a pacemaker whereby it could generate [[Action potential|action potential to]] control heart rate<ref name="null">Quain, Jones. (1908) Quain's Elements of Anantomy, 4. London: Longmans, Green and Co.</ref>. This is essential as it marks the start of the electrical conduction of the [[Heart|heart]]<ref name="null">Quain, Jones. (1908) Quain's Elements of Anantomy, 4. London: Longmans, Green and Co.</ref>. | ||
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Revision as of 01:57, 22 October 2015
The atria (singular atrium) are the upper chambers in the heart that receive blood from large veins and deliver it to ventricles. They have thin walls compared to ventricles, as the blood is only moving a short distance down to the ventricles, therefore little muscle is needed compared to ventricles which pump the blood over larger distances.[1] Atria are involved in the first stages of the cardiovascular cycle mediated by the Sinoatrial Node (SAN). A wave of depolarization sweeps over the the atria causing them to contract, which forces blood from the atria into the ventricles. The SAN acts a pacemaker whereby it could generate action potential to control heart rate[2]. This is essential as it marks the start of the electrical conduction of the heart[2].