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
Jane (given name) when she was plaintiff in the landmark American case Roe v. Wade. Jane Doe is used in United States police investigations when the identity of a female victim is unknown or incorrect, and by hospitals to refer to a female corpse or patient whose identity is unknown. Jane (given name) Jane is a feminine given name. It is the English form of the Old French name Jehanne, which was an old feminine form of the male name Johannes or Ioannes (also the source of the English name John), a Latin form of the Greek name (Iōannēs), which is derived from