Atrium (heart) similar function. Some animals (amphibians and reptiles) have a three-chambered heart, in which the blood from each atrium is mixed in the single ventricle before being pumped to the aorta. In these animals, the left atrium still serves the purpose of collecting blood from the pulmonary veins. In some fish, the circulatory system is very simple: a two-chambered heart including one atrium and one ventricle. Among sharks, the heart consists of four chambers arranged serially (and therefore called a serial heart): blood flows into the most posterior chamber, the sinus venosus, and then to the atrium which moves it to
Brendan (given name) There is no etymological link between "Brendan" and "Brenda". This feminine given name, pronounced , is thought to be derived from the Old Norse element "brand", meaning "(flaming) sword". In most cases, the masculine given name "Brandon", pronounced , is considered to be derived from the surname "Brandon", which is in turn derived from two Old English elements. In some cases, the masculine given name "Brennan" may be used as a contracted form of "Brendan". Brennan is etymologically unrelated to "Brendan". It is derived from the surname "Brennan", which is an Anglicised form of the Irish "Ó Braonáin". The popularity