Human red blood cells

Red blood cells are the most common type of blood cell and are the vertebrate body's principal means of delivering oxygen from the lungs or gills to body tissues via the blood. Red blood cells are also known as RBCs or erythrocytes (from Greek erythros for "red" and kytos for "hollow", nowadays translated as "cell"). A schistocyte is a red blood cell undergoing fragmentation, or a fragmented part of a red blood cell. A micrograph of red blood cells, taken from the site http://www. ... A blood cell is any cell of any type normally found in blood. ... Groups Conodonta Hyperoartia Petromyzontidae (lampreys) Pteraspidomorphi (early jawless fish) Thelodonti Anaspida Cephalaspidomorphi (early jawless fish) Galeaspida Pituriaspida Osteostraci Gnathostomata (jawed vertebrates) Placodermi Chondrichthyes (cartilaginous fish) Acanthodii Osteichthyes (bony fish) Actinopterygii (ray-finned fish) Sarcopterygii (lobe-finned fish) Actinistia (coelacanths) Dipnoi (lungfish) Tetrapoda Amphibia Amniota Sauropsida/(Reptiles) Aves (Birds) Synapsida Mammalia... With regard to living things, a body is the integral physical material of an individual, and contrasts with soul, personality and behavior. ... General Name, Symbol, Number oxygen, O, 8 Chemical series nonmetals Group, Period, Block 16, 2, p Appearance colorless Atomic mass 15. ... The lungs flank the heart and great vessels in the chest cavity. ... gills of a Smooth Newt In aquatic organisms, gills are a respiratory organ for the extraction of oxygen from water and for the excretion of carbon dioxide. ... Red blood cells (erythrocytes) are present in the blood and help carry oxygen to the rest of the cells in the body Blood is a circulating tissue composed of fluid plasma and cells (red blood cells, white blood cells, platelets). ...

The average life cycle of a red blood cell is 120 days. Every second 2.5 million of red blood cells are destroyed. However that only represents only 0.00001% of the total 30 trillion cells. Our bones are continues producing new blood cells. It takes approximately four days for our bones to make new red blood cells.

Vertebrate erythrocytes

Erythrocytes consist mainly of hemoglobin, a complex molecule containing heme groups whose iron molecules temporarily link to oxygen molecules in the lungs or gills and release them throughout the body. Hemoglobin also carries some of the waste product carbon dioxide back from the tissues. (In humans, less than 2% of the total oxygen, and most of the carbon dioxide, are held in solution in the blood plasma). The heme of the red blood cell's hemoglobin gives blood its red color. A related compound, myoglobin, acts to store oxygen in muscle cells. 3-dimensional structure of hemoglobin Hemoglobin or haemoglobin (frequently abbreviated as Hb, PDB 1A3N) is the iron-containing oxygen-transport metalloprotein in the red cells of the blood in mammals and other animals. ... A hæm or heme is a metal-containing cofactor that consists of an iron atom contained in the center of a large heterocyclic organic ring called a porphyrin. ... General Name, Symbol, Number iron, Fe, 26 Chemical series transition metals Group, Period, Block 8, 4, d Appearance lustrous metallic with a grayish tinge Atomic mass 55. ... | Melting point | -57 °C (216 K), pressurized |- | Boiling point | -78 °C (195 K), sublimes |- | Acidity (pKa) | 6. ... Blood plasma is the liquid component of blood, in which the blood cells are suspended. ... Red is a color at the lowest frequencies of light discernible by the human eye. ... Myoglobin 3D structure. ... A top-down view of skeletal muscle Muscle is a contractile form of tissue. ...

The keeping of oxygen-binding proteins in cells (rather than having them dissolved in body fluid) was an important step in the evolution of vertebrates; it allows for less viscous blood and longer transport ways of oxygen. The Pitch Drop Experiment at the University of Queensland. ...

Mammalian erythrocytes

Erythrocytes in mammals are anucleate when mature, meaning that they don't have a cell nucleus and thus no DNA. (The erythrocytes of nearly all other vertebrates have nuclei; the only known exception are salamanders of the Batrachoseps genus.) Erythrocytes also lose their other organelles including their mitochondria and produce energy by fermentation, via glycolysis of glucose followed by lactic acid production. Like most cell types, red cells do not have an insulin receptor and thus glucose uptake is not regulated by insulin. Orders Subclass Embrithopoda (extinct) Subclass Creodonta (extinct) Hyaenodontidae Oxyaenidae Subclass Multituberculata (extinct) Plagiaulacida Cimolodonta Subclass Palaeoryctoides (extinct) Subclass Triconodonta (extinct) Subclass Placentalia Afrosoricida Artiodactyla Carnivora Cetacea Chiroptera Dermoptera Desmostylia (extinct) Hyracoidea Insectivora Lagomorpha Macroscelidea Perissodactyla Pholidota Primates Proboscidea Rodentia Scandentia Sirenia Tubulidentata Xenarthra Subclass Marsupialia Dasyuromorphia Didelphimorphia Diprotodontia Microbiotheria Notoryctemorphia... In cell biology, the nucleus (from Latin nucleus or nuculeus, kernel) is an organelle, found in all eukaryotic cells, which contains most of the cells genetic material. ... Space-filling model of a section of DNA molecule Deoxyribonucleic acid (DNA) is a nucleic acid that contains the genetic instructions specifying the biological development of all cellular forms of life (and many viruses). ... Groups Conodonta Hyperoartia Petromyzontidae (lampreys) Pteraspidomorphi (early jawless fish) Thelodonti Anaspida Cephalaspidomorphi (early jawless fish) Galeaspida Pituriaspida Osteostraci Gnathostomata (jawed vertebrates) Placodermi Chondrichthyes (cartilaginous fish) Acanthodii Osteichthyes (bony fish) Actinopterygii (ray-finned fish) Sarcopterygii (lobe-finned fish) Actinistia (coelacanths) Dipnoi (lungfish) Tetrapoda Amphibia Amniota Sauropsida/(Reptiles) Aves (Birds) Synapsida Mammalia... Suborders Cryptobranchoidea Salamandroidea Sirenoidea Salamander is the common name applied to approximately 500 amphibian vertebrates with slender bodies, short legs, and long tails (order Caudata or Urodela). ... Species 19 species, see text Slender Salamanders is the name often given to Plethodontid (lungless) salamanders of the genus Batrachoseps. ... Schematic of typical animal cell, showing subcellular components. ... Mitochondria are visible as thread-like structures in the light microscope. ... In its strictest sense, fermentation (formerly called zymnosis) is the energy-yielding anaerobic metabolic breakdown of a nutrient molecule, such as glucose, without net oxidation. ... Glycolysis is a term referring to a series of biochemical reactions by which a molecule of glucose is oxidized to two molecules of pyruvic acid. ... A space-filling model of glucose Glucose, a simple monosaccharide sugar, is one of the most important carbohydrates and is used as a source of energy in animals and plants. ... Lactic acid (α-hydroxypropionic acid) is a chemical compound that plays a role in several biochemical processes. ... In molecular biology, the insulin receptor is a transmembrane receptor that is activated by insulin. ... The structure of insulin Red: carbon; green: oxygen; blue: nitrogen; pink: sulfur. ...

Mammalian erythrocytes have a biconcave shape: flattened and depressed in the center. This shape (as well as the loss of organelles) optimizes the cell for the exchange of oxygen with its surroundings. The cells are flexible so as to fit through tiny capillaries, where they release their oxygen load. Erythrocytes are circular, except in the camel family Camelidae, where they are oval. In geometry, concavity is a property of certain geometric figures, and in calculus, a property of certain graphs of functions. ... Capillaries are the smallest of a bodys blood vessels, measuring 5-10 μm. ... Species Camelus bactrianus Camelus dromedarius A camel is either of the two species of large even-toed ungulate in the genus Camelus, the Dromedary (Single hump) and the Bactrian Camel (Double hump). ... Species  Lama glama  Lama pacos  Lama guanicoe  Vicugna vicugna  Camelus dromedarius  Camelus bactrianus The four llamas and two camels are camelids: members of the biological family Camelidae, the only family in the suborder Tylopoda. ...

The spleen acts as a reservoir of red blood cells, but this effect is somewhat limited in humans. In some other mammals such as dogs and horses, the spleen sequesters large numbers of red blood cells that are dumped into the blood during times of exertion stress, yielding a higher oxygen transport capacity. The spleen is a ductless, vertebrate gland that is not necessary for life but is closely associated with the circulatory system, where it functions in the destruction of old red blood cells and removal of other debris from the bloodstream, and also in holding a reservoir of blood. ... Trinomial name Canis lupus familiaris (Linnaeus, 1758) The dog is a canine carnivorous mammal that has been domesticated for at least 14,000 years and perhaps for as long as 150,000 years based on recent evidence. ... Binomial name Equus caballus Linnaeus, 1758 The Horse (Equus caballus) is a sizeable ungulate mammal, one of the seven modern species of the genus Equus. ...

Human erythrocytes

The diameter of a typical human erythrocyte is 6–8 µm. Adult humans have roughly 2–3 × 10¹³ red blood cells at any given time (women have about 4 million to 5 million erythrocytes per cubic millimeter (microliter) of blood and men about 5 million to 6 million; people living at high altitudes with low oxygen concentration will have more). Red blood cells are thus much more common than the other blood particles: there are about 4,000–11,000 white blood cells and about 150,000–400,000 platelets in a cubic millimeter of human blood. The red blood cells store collectively about 3.5 grams of iron; that's more than five times the iron stored by all the other tissues combined. To help compare different orders of magnitude this page lists lengths between 1 micrometre and 10 micrometres (10-6 and 10-5 m). ... To help compare orders of magnitude this page lists dimensionless numbers between 1012 and 1015: See also Orders of magnitude (numbers) Categories: Stub | Orders of magnitude (numbers) ... A 250 ml bag of newly collected platelets. ... General Name, Symbol, Number iron, Fe, 26 Chemical series transition metals Group, Period, Block 8, 4, d Appearance lustrous metallic with a grayish tinge Atomic mass 55. ...

The blood types of humans are due to variations in surface glycoproteins of erythrocytes. A blood type is a description of an individuals characteristics of red blood cells due to substances (carbohydrates and proteins) on the cell membrane. ... A glycoprotein is a macromolecule composed of a protein and a carbohydrate (a sugar). ...

The process by which red blood cells are produced is called erythropoiesis. Erythrocytes are continuously being produced in the red bone marrow of large bones. (In the embryo, the liver is the main site of red blood cell production.) The production can be stimulated by the hormone erythropoietin (EPO), which is used for doping in sports. Erythrocytes develop in about 7 days and live a total of about 120 days. The aging cells swell up to a sphere-like shape and are engulfed by phagocytes, destroyed and their materials are released into the blood. The main sites of destruction are the liver and the spleen. The heme constituent of hemoglobin is eventually excreted as bilirubin. Erythropoiesis is the process by which red blood cells (erythrocytes) are produced. ... Bone marrow is the tissue comprising the center of large bones. ... Embryos (and one tadpole) of the wrinkled frog (Rana rugosa). ... The liver is an organ in vertebrates, including humans. ... A hormone (from Greek horman - to set in motion) is a chemical messenger from one cell (or group of cells) to another. ... Erythropoietin (or EPO) is a glycoprotein hormone that is a growth factor for erythrocyte (red blood cell) precursors in the bone marrow. ... In sports, doping refers to the use of performance-enhancing drugs, such as anabolic steroids, particularly those that are forbidden by the organizations that regulate competitions. ... A phagocyte is a cell that ingests (and destroys) foreign matter, such as microorganisms or debris via a process known as phagocytosis, in which these cells ingest and kill offending cells by cellular digestion. ... The spleen is a ductless, vertebrate gland that is not necessary for life but is closely associated with the circulatory system, where it functions in the destruction of old red blood cells and removal of other debris from the bloodstream, and also in holding a reservoir of blood. ... Bilirubin is a yellow breakdown product of haem (heme in American English). ...

Red blood cells can be separated from blood plasma by centrifugation. During plasma donation, the red blood cells are pumped back into the body right away, and the plasma is collected. Some athletes have tried to improve their performance by doping their blood: first about 1 liter of their blood is extracted, then the red blood cells are isolated, frozen and stored, to be reinjected shortly before the competition. (Red blood cells can be conserved for 5 weeks at −78 °C.) This practice is hard to detect but may endanger the human cardiovascular system because it is not equipped to deal with blood of the resulting higher viscosity. Blood plasma is the liquid component of blood, in which the blood cells are suspended. ... Centrifugation involves the use of the centrifugal force for the separation of mixtures. ... The circulatory system or cardiovascular system is the organ system which circulates blood around the body of most animals. ... The Pitch Drop Experiment at the University of Queensland. ...

Diseases and diagnostic tools

Affected by Sickle-cell disease, red blood cells alter shape and threaten to damage internal organs.

Blood diseases involving the red blood cells include: Micrograph of sickled red blood cells, taken from the NIH (US government agency) site at http://www. ... Sickle-shaped red blood cells Sickle-cell disease is a genetic disorder in which red blood cells may change shape under certain circumstances. ... Blood diseases affect the production of blood and its components, such as blood cells, hemoglobin, blood proteins, the mechanism of coagulation, etc. ...

• Anemias (or anaemias) are diseases characterized by low oxygen transport capacity of the blood, because of low red cell count or some abnormality of the red blood cells or the hemoglobin.
  • Iron deficiency anemia is the most common anemia; it occurs when the dietary intake or absorption of iron is insufficient, and hemoglobin, which contains iron, cannot be formed
  • Sickle-cell disease is a genetic disease which leads to mis-shaped red blood cells.
  • Thalassemia is a genetic disease that results in the production of abnormal hemoglobin molecules.
  • Spherocytosis is a genetic disease that causes a defect in the red blood cell's cytoskeleton, causing the RBCs to be small, sphere-shaped, and fragile instead of donut-shaped and flexible.
  • Pernicious anemia is an autoimmune disease where the body lacks intrinsic factor, required to absorb vitamin B12 from food. Vitamin B12 is needed for the production of hemoglobin.
  • Aplastic anemia is caused by the inability of the bone marrow to produce blood cells.
• The malaria parasite spends part of its life-cycle in red blood cells and feeds on hemoglobin. Both sickle-cell disease and thalassemia are more common in malaria areas, because these mutations convey some protection against the parasite.
• Polycythemias (or erythrocytoses) are diseases characterized by a surplus of red blood cells. The increased viscosity of the blood can cause a number of symptoms.
  • In polycythemia vera the increased number of red blood cells results from an abnormality in the bone marrow.

Several blood tests involve red blood cells, including the RBC count (the number of red blood cells per volume of blood) and the hematocrit (percentage of blood volume occupied by red blood cells). The blood type needs to be determined to prepare for a blood transfusion or an organ transplantation. This article discusses the medical condition. ... Iron deficiency anemia is the most common type of anemia, and the most common cause of microcytic anemia. ... General Name, Symbol, Number iron, Fe, 26 Chemical series transition metals Group, Period, Block 8, 4, d Appearance lustrous metallic with a grayish tinge Atomic mass 55. ... Sickle-shaped red blood cells Sickle-cell disease is a genetic disorder in which red blood cells may change shape under certain circumstances. ... Thalassemia (American English) (or Thalassaemia in British English) is an inherited disease of the red blood cells, classified as a hemoglobinopathy. ... Spherocytosis is an auto-hemolytic anemia (a disease of the blood) characterized by the production of red blood cells that are sphere-shaped, rather than donut-shaped. ... The cytoskeleton is a cellular scaffolding or skeleton contained, as all other organelles, within the cytoplasm. ... Pernicious anemia refers to a type of autoimmune anemia. ... Autoimmune diseases arise from an overactive immune response of the body against substances and tissues normally present in the body. ... Intrinsic factor is a glycoprotein produced by the parietal cells of the stomach. ... Cobalamin or vitamin B12 is a chemical compound that is also known as cyanocobalamine. ... Aplastic anemia is a condition where the bone marrow does not produce enough, or any, new cells to replenish the blood cells. ... Bone marrow is the tissue comprising the center of large bones. ... Red blood cell infected with Malaria (Italian: bad air; formerly called ague or marsh fever in English) is an infectious disease which in humans causes about 350-500 million infections and approximately 1. ... Sickle-shaped red blood cells Sickle-cell disease is a genetic disorder in which red blood cells may change shape under certain circumstances. ... Thalassemia (American English) (or Thalassaemia in British English) is an inherited disease of the red blood cells, classified as a hemoglobinopathy. ... Polycythemia is a condition in which there is a net increase in the total circulating erythrocyte (red blood cell) mass of the body. ... Polycythemia is a condition in which there is a net increase in the total circulating erythrocyte (red blood cell) mass of the body. ... Blood tests are laboratory tests done on blood to gain an appreciation of disease states and the function of organs. ... The hematocrit (Ht) or packed cell volume (PCV) is the proportion of blood volume that is occupied by red blood cells. ... A blood type is a description of an individuals characteristics of red blood cells due to substances (carbohydrates and proteins) on the cell membrane. ... Blood transfusion is the taking of blood or blood-based products from one individual and inserting them into the circulatory system of another. ... An organ transplant is the transplantation of an organ (or part of one) from one body to another, for the purpose of replacing the recipients damaged or failing organ with a working one from the donor. ...

History

In 1658, the Dutch Jan Swammerdam was the first to describe red blood cells; he had used an early microscope. Events January 13 - Edward Sexby, who had plotted against Oliver Cromwell, dies in Tower of London February 6 - Swedish troops of Charles X Gustav of Sweden cross The Great Belt (Storebælt) in Denmark over frozen sea May 1 - Publication of Hydriotaphia, Urn Burial and The Garden of Cyrus by... Jan Swammerdam (February 12, 1637 - February 17, 1680) was a Dutch scientist. ... 1852 microscope Compound microscope made by John Cuff in 1750 A microscope (Greek: micron = small and scopos = aim) is an instrument for viewing objects that are too small to be seen by the naked or unaided eye. ...

External links

• Database of vertebrate erythrocyte sizes