Red blood cell

Red blood cells (RBCs), also called erythrocytes, are the most common type of blood cell and the vertebrate organism's principal means of delivering oxygen (O₂) to the body tissues—via blood flow through the circulatory system. RBCs take up oxygen in the lungs or gills and release it into tissues while squeezing through the body's capillaries.

The cytoplasm of erythrocytes is rich in hemoglobin, an iron-containing biomolecule that can bind oxygen and is responsible for the red color of the cells. The cell membrane is composed of proteins and lipids, and this structure provides properties essential for physiological cell function such as deformability and stability while traversing the circulatory system and specifically the capillary network.

In humans, mature red blood cells are flexible and oval biconcave disks. They lack a cell nucleus and most organelles, in order to accommodate maximum space for hemoglobin; they can be viewed as sacks of hemoglobin, with a plasma membrane as the sack. Approximately 2.4 million new erythrocytes are produced per second in human adults. The cells develop in the bone marrow and circulate for about 100–120 days in the body before their components are recycled by macrophages. Each circulation takes about 20 seconds. Approximately a quarter of the cells in the human body are red blood cells. Nearly half of the blood's volume (40% to 45%) is red blood cells.

Reading Blue Coat School

Reading Blue Coat School is a boys' independent school (and co-educational in the 6th form) in Holme Park in the village of Sonning, in the English county of Berkshire, to the east of the town of Reading. It is situated beside the River Thames, and was established in 1646 by Richard Aldworth, who named it "Aldworth's Hospital".

History

Established in 1646 at the height of the English Civil War, a wealthy London merchant, Richard Aldworth of Stanlake Park, left the Corporation of Reading the sum of £4,000, the proceeds of which were to be devoted to "the education and upbringing of twenty poor male children, being the children of honest, religious poor men in the town of Reading." From this bequest, which in 17th century terms was quite substantial, originated the Aldworth's Hospital charity school now better known as the Reading Blue Coat School.

Aldworth, who had been a governor of Christ's Hospital in London, modelled the new foundation on his former school, the boys being required to wear the Bluecoat attire of gown, yellow stockings, and buckled shoes. Aldworth's Will further stipulated that the Master of the new school should be "an honest, Godly and learned man" who for his "paines" would receive a stipend of £30 a year. His duties were to include the instruction of reading, writing and ciphering and to "teach the Catechism in the points of Christian Religion."