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
Douglas (given name) Douglas (given name) Douglas is a Scottish masculine given name which originated from the surname "Douglas". Although today the name is almost exclusively given to boys, it was used as girls name in the seventeenth and eighteenth centuries, in the north of England. The Scottish surname "Douglas" was borne by one of the most powerful families of the Kingdom of Scotland (the Earls of Douglas, Angus, Morton, Dukes of Hamilton and others). It has sometimes been stated that the given name is connected with the given name "Dougal", although it is more likely derived from the surname already mentioned. Linguistically,