Atria

From The School of Biomedical Sciences Wiki
Revision as of 02:59, 21 October 2015 by 150015857 (talk | contribs)
Jump to navigation Jump to search

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.

References:

  1. ↑ Pocock G., Richards C. (2006) Human Physiology: The Basis of Medicine, 3rd Edition, Oxford University Press
  2. ↑ Quain, Jones. (1908) Quain's Elements of Anantomy, 4. London: Longmans, Green & Co.
Retrieved from "https://teaching.ncl.ac.uk/bms/wiki//index.php?title=Atria&oldid=13632"