2Red blood cellsThis image shows red blood cells, clearly displaying their biconcave disc shape.Credit: Annie Cavanagh, Wellcome Images.
3Blood bag BIGPICTUREEDUCATION.COM A laboratory technician holding a blood bag that contains group A, Rh-positive blood ready for transfusion.Credit: Wellcome Library, LondonBIGPICTUREEDUCATION.COM
4Sickle-cell anaemia BIGPICTUREEDUCATION.COM Sickle-cell anaemia is a blood disease that causes the cell to form a characteristic sickle shape. This change in shape affects the cell's ability to carry haemoglobin. This image shows a normal red blood cell (background, coloured red) and red blood cell affected by sickle-cell anaemia (foreground).Credit: EM Unit, UCL Medical School, Royal Free Campus, Wellcome ImagesBIGPICTUREEDUCATION.COM
5Sickled and other red blood cells A scanning electron micrograph image of sickled and other red blood cells, shown coloured red.Credit: EM Unit, UCL Medical School, Royal Free Campus, Wellcome Images
6Molecular model of haemoglobin and sickle cell disease A molecular model of haemoglobin affected by sickle cell disease.Credit: T Blundell and N Campillo, Wellcome Images..
7Ruptured blood vesselA colour-enhanced image of red blood cells leaking out of a ruptured blood vessel. This is due to a mutation that causes the blood vessels to be more fragile than normal, leading to an increased rate of haemorrhaging. Credit: Anne Weston, LRI, CRUK, Wellcome Images
8Colour-enhanced blood clot This image shows many red blood cells and a single white blood cell held together in a meshwork of fibrin (brown).Credit: Anne Weston, LRI, CRUK, Wellcome Images
9Blood clot on a sticking plaster A scanning electron micrograph image of the underside of a sticking plaster that has been used to treat a razor blade cut. Red blood cells (shown in red) and thin fibres of the protein fibrin (beige) can be seen between the gauze fibres of the plaster (blue-grey). Fibrin is a protein formed from the conversion of clotting factors in the blood; the fibrin fibres trap blood cells and platelets to form a solid clot. This not only prevents further bleeding but also protects the open wound from infection.Credit: Anne Weston, LRI, CRUK, Wellcome Images
10Blood clot forming over a wound A colour-enhanced scanning electron micrograph image of a blood clot with squamous tissue visible beneath. As a blood clot on a surface injury dries out, it forms a protective scab over the wound, allowing new skin to grow underneath.Credit: David Gregory and Debbie Marshall, Wellcome Images
11Blood clotA scanning electron microscope image of a blood clot that shows red blood corpuscles and fibrin.Credit: David Gregory and Debbie Marshall, Wellcome Images
12Blood clot and new cells under fibrin A scanning electron microscope image of blood clot, showing new cells under fibrin clot.Credit: David Gregory and Debbie Marshall, Wellcome Images
13Fibrin blood clotA scanning electron microscope image of a blood clot, showing new cells under a fibrin clot. Fibrin, which is also called Factor 1a, acts as a mesh and forms blood clots (with platelets) to trap blood cells and prevent further loss of blood as the wound heals.Credit: David Gregory and Debbie Marshall, Wellcome Images
14Red blood corpuscles, discoid and stimulated platelets A scanning electron microscope image of red blood corpuscles, discoid and stimulated platelets.Credit: David Gregory and Debbie Marshall, Wellcome Images
15Blood corpuscles in clot A scanning electron micrograph image of red blood corpuscles and a single white blood cell entangled in the fibrin mesh of a clot.Credit: David Gregory and Debbie Marshall, Wellcome Images