red blood cell

American  

noun

1. Physiology. one of the cells of the blood, which in mammals are enucleate disks concave on both sides, contain hemoglobin, and carry oxygen to the cells and tissues and carbon dioxide back to the respiratory organs. RBC

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red blood cell British  

noun

1. another name for erythrocyte

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red blood cell Scientific  

1. Any of the oval or disc-shaped cells that circulate in the blood of vertebrate animals, contain hemoglobin, and give blood its red color. The hemoglobin in red blood cells binds to oxygen for transport and delivery to body tissues, and it transports carbon dioxide, excreted as a metabolic waste product, out of the tissues. The red blood cells of mammals have no nucleus, while those of other vertebrates do contain nuclei. Red blood cells are formed in the bone marrow.

2. Also called erythrocyte

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Closer Look

While 60 percent of the US population is eligible to donate blood, only about 5 percent does. There is no substitute for human blood, which is used for numerous medical situations, including surgery for trauma, cancer treatment, organ transplants, burns, open heart surgeries, anemia, clotting disorders, and treating premature babies. The average red blood cell transfusion is 3.4 pints. Blood, which is made in the bone marrow, has four main components—red cells, platelets, plasma, and white cells. Red blood cells, or erythrocytes, transport oxygen from the lungs to the rest of the body. These disk-shaped cells contain hemoglobin, an iron-containing protein that picks up oxygen molecules as the blood exchanges gases in the lungs. The red blood cells, which can live about 120 days in the circulatory system, deliver oxygen to the far reaches of the body, where it is released for use by other cells, such as those of the brain and muscles. Red blood cells also pick up carbon dioxide and return it to the lungs to be exhaled. All animals have some form of oxygen distribution system, but only vertebrates use red blood cells. In some invertebrates, such as the earthworm, oxygen is transported using hemoglobin that is freely dissolved in the blood. Other invertebrates don't use hemoglobin at all. The horseshoe crab, for instance, uses copper instead of iron, making its blood blue instead of red.

Etymology

Origin of red blood cell

First recorded in 1905–10

Example Sentences

And Dr. Doctor’s red blood cell particle is actually slightly more effective than a human red blood cell at releasing oxygen.

From Slate • Sep. 1, 2025

Untreated, the clots cause organ damage and low red blood cell and platelet counts.

From BBC • Mar. 6, 2025

There was bone cancer, chemo and red blood cell aplasia that left him needing regular transfusions.

From Los Angeles Times • May 29, 2024

One potential complication is hemolytic uremic syndrome, or HUS, which can occur when red blood cell and platelet levels drop.

From Seattle Times • May 7, 2024

But what made a red blood cell acquire a sickle shape?

From "The Gene" by Siddhartha Mukherjee