Heart depending on what is counted as a chamber. The atrium and ventricle are sometimes considered "true chambers", while the others are considered "accessory chambers". Primitive fish have a four-chambered heart, but the chambers are arranged sequentially so that this primitive heart is quite unlike the four-chambered hearts of mammals and birds. The first chamber is the sinus venosus, which collects deoxygenated blood from the body through the hepatic and cardinal veins. From here, blood flows into the atrium and then to the powerful muscular ventricle where the main pumping action will take place. The fourth and final chamber is the
Logan (given name) Logan (given name) The given name Logan is derived from the Scottish surname "Logan", which is in turn derived from a place name. The likely origin of this surname is a place located near Auchinleck, in Ayrshire. The place name is derived from the Scottish Gaelic "lagan", which is a diminutive of "lag", which in turn means "hollow". The given name is borne by males and females. The given name was the 17th most popular name for baby boys born in the United States in 2007 and was the 455th most popular name for baby girls born there in 2007.