Heart

The heart is a muscular organ in humans and other animals, which pumps blood through the blood vessels of the circulatory system. Blood provides the body with oxygen and nutrients, and also assists in the removal of metabolic wastes. The heart is located in the middle compartment of the mediastinum in the chest.

In humans, other mammals, and birds, the heart is divided into four chambers: upper left and right atria; and lower left and right ventricles. Commonly the right atrium and ventricle are referred together as the right heart and their left counterparts as the left heart. Fish in contrast have two chambers, an atrium and a ventricle, while reptiles have three chambers. In a healthy heart blood flows one way through the heart due to heart valves, which prevent backflow. The heart is enclosed in a protective sac, the pericardium, which also contains a small amount of fluid. The wall of the heart is made up of three layers: epicardium, myocardium, and endocardium.

OST

OST may refer to:

Music

Science and technology

Organizations

Producer

Producer or producers may refer to:

Occupations

Music download

A music download is the digital transfer of music via the Internet into a device capable of decoding and playing it, such as a home computer, MP3 player or Smart Phone. This term encompasses both legal downloads and downloads of copyright material without permission or legal payment. According to a Nielsen report, downloadable music accounted for 55.9% of all music sales in the US in 2012. As of January 2011, Apple's iTunes Store alone made $1.1 billion of revenue in the first quarter of its fiscal year.

Online music stores

Popular online music stores that sell downloadable singles and albums include the iTunes Store, Amazon MP3, fairsharemusic, eMusic, Google Play, CD Universe, Nokia Music Store, TuneTribe, Xbox Music and MyMusic.com.ng. Paid downloads are sometimes encoded with Digital Rights Management that restricts copying the music or playing purchased songs on certain digital audio players. They are almost always compressed using a lossy codec (usually MPEG-1 Layer 3, Windows Media, or AAC), which reduces file size and bandwidth requirements. These music resources have been created as a response to expanding technology and needs of customers that wanted easy, quick access to music. Their business models respond to the "download revolution" by making legal services attractive for users.

The Producers

The Producers may refer to:

Titled works

Bands