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 Given name A given name (also known as a first name, forename or Christian name) is a part of a person's personal name. It identifies a specific person, and differentiates that person from the other members of a group (typically a family or clan) who have a common surname. The term "given name" refers to the fact that the name usually is bestowed upon a person, normally to a child by his or her parents at or close to the time of birth. A Christian name, a first name which historically was given at baptism, is now also typically given