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
Maria (given name) Maria (given name) Maria is a feminine given name. It is given in many languages influenced by Latin Christianity. It has its origin as the feminine form of the Roman name Marius (see Maria (gens)), and, after Christianity religion has spread across the Roman empire, it became the Latinised form of the name of Miriam - Mary, mother of Jesus. "Maria" (Μαρία) is a form of the name used in the New Testament, standing alongside "Mariam" Μαριάμ. It reflects the Syro-Aramaic name "Maryam", which is in turn derived from the Biblical Hebrew name "Miriam". As a result of their similarity