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blood: Quick Facts

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News •

Scientists just found dinosaur blood that survived 115 million years • Nov. 6, 2026, 6:32 AM ET (Science Daily)
Watch: Blood donors get a Halloween fright in Thailand • Oct. 31, 2026, 8:50 AM ET (BBC)

Photos and Videos

Blood plasma
Illustration of a blood vessel with a cutaway view showing red blood cells, white blood cells, platelets, and plasma, each labeled to highlight the main components of blood.
Close-up illustration of multiple human red blood cells with their characteristic disc shape, floating against a red background.
Diagram of the hemoglobin tetramer showing two alpha and two beta subunits, each in a different color, with four heme groups labeled, each containing a central iron atom for oxygen binding.
Labeled illustration of a macrophage showing its internal organelles and the process of engulfing and digesting bacteria, with bacteria drawn outside and inside the cell as it undergoes phagocytosis.
MRSA and neutrophil
A single purple-stained monocyte, a type of white blood cell, is visible among many pink-stained red blood cells in a human blood smear under a microscope.
Human lymphocyte
Human T cell
Platelet
Observe a red blood cell as it travels from the heart to the lungs and other body tissues
Function of red blood cells explained
Gloved hands hold a blood sample tube above a rack of vials in a laboratory, illustrating blood analysis in human body science.
Close-up of a medical blood bag filled with red blood, showing attached tubes and connectors against a blurred background.
Learn about sickle cell anemia and blood behavior in sickle cell patients
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Related Topics and References

Topics

Key People

Stephen Hales
Stephen Hales
English scientist
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Edwin Joseph Cohn
American biochemist
William Harvey
William Harvey
English physician
Claude Bernard
Claude Bernard
French scientist
Marcello Malpighi
Marcello Malpighi
Italian scientist
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Bernardo Alberto Houssay
Argentine physiologist
Portrait painting of physician Charles Drew in a white coat, seated at a desk with a microscope, holding a notebook, against a plain background. Painted by Betsy Graves Reyneau.
Charles Richard Drew
American physician
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Walter Bradford Cannon
American neurologist and physiologist
Nuttall, George Henry Falkiner
George Henry Falkiner Nuttall
British biologist
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Ernst Felix Hoppe-Seyler
German physician

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