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
Given name is commonly used in Spanish-speaking countries to acknowledge the families of both parents. Today the order can also be changed legally in Spain and Uruguay using "given name – mother's family name – father's family name". In many Western cultures, people often have more than one given name. One of those which is not the first in succession might be used exclusively as the name which that person goes by, such as in the cases of John Edgar Hoover and Mary Barbara Hamilton Cartland. A child's given name or names are usually chosen by the parents soon after birth. If