Atrium (heart) similar function. Some animals (amphibians and reptiles) have a three-chambered heart, in which the blood from each atrium is mixed in the single ventricle before being pumped to the aorta. In these animals, the left atrium still serves the purpose of collecting blood from the pulmonary veins. In some fish, the circulatory system is very simple: a two-chambered heart including one atrium and one ventricle. Among sharks, the heart consists of four chambers arranged serially (and therefore called a serial heart): blood flows into the most posterior chamber, the sinus venosus, and then to the atrium which moves it to
Sandra (given name) Sandra (given name) Sandra is a female name, which is often used as a short form for Alexandra or Cassandra. Alexandra is a feminine form of the male name Alexander, which is a romanization of the Greek name Ἀλέξανδρος "Alexandros". It is generally interpreted to mean "protector of man" or "defender of man". The name Cassandra is also from the Greek (: "she who entangles men"). Cassandra is known in Greek mythology, as the daughter of King Priam and Queen Hecuba of Troy. She was loved by Apollo and given the gift of prophecy but when she did not fall