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
Which? trading businesses, for instance subscriptions to "Which?" magazine, which are donated to the campaigning part of the organisation to fund advocacy activity and inform the public about consumer issues. "Which?" magazine maintains its independence by not accepting advertising, and the organisation receives no government funding. The Consumers' Association is the largest consumer organisation in the UK, with over 573,000 subscribers to its magazine. Until 2006, the association used prize draws similar to those of "Reader's Digest" to attract subscribers, but following criticism they were discontinued. The Association now attracts subscribers to its publications with free mini-guides and trial offers. The