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单词 target erythrocyte
释义 DictionarySeeerythrocyteMedicalSeeERYTHROCYTES: Note the different size and shape of the red blood cellsA blood cell (i.e., a circulating cell that contains hemoglobin and carries oxygen to tissue). Each erythrocyte is a nonnucleated, biconcave disk averaging 7.7 µm in diameter. An erythrocyte has a typical cell membrane and an internal stroma made of lipids and proteins to which more than 200 million molecules of hemoglobin are attached. The total surface area of the erythrocytes of an average adult is 3820 sq m, or about 2000 times more than the external total body surface area. Synonym: red blood cell; red blood corpuscle; red cell; red corpuscle See: illustration

Number

In a normal person, the number of erythrocytes averages about 5,000,000/µL (5,500,000 for men and 4,500,000 for women). The total number in an average-sized person is about 35 trillion. The number per µL varies with age (higher in infants), time of day (lower during sleep), activity and environmental temperature (increasing with both), and altitude. People living at altitudes of 10,000 ft (3048 m) or more may have an erythrocyte count of 8,000,000/µL or more.

If a person has a normal blood volume of 5 L (70 mL/ kg of body weight) and 5,000,000 erythrocytes per µL of blood, and the erythrocytes live 120 days, the red bone marrow must produce 2,400,000 erythrocytes per second to maintain this erythrocyte count.

Physiology

The primary function of erythrocytes is to carry oxygen. The hemoglobin also contributes to the acid-base balance of the blood by acting as a buffer for the transport of carbon dioxide in the plasma as bicarbonate ions.

Development

Erythrocyte formation (erythropoiesis) in adults takes place in the bone marrow, principally in the vertebrae, ribs, sternum, hip bone, diploë of cranial bones, and proximal ends of the humerus and femur. erythrocytes arise from large nucleated stem cells (promegaloblasts), which give rise to pronormoblasts, in which hemoglobin appears. These become normoblasts, which extrude their nuclei. erythrocytes at this stage possess a fine reticular network and are known as reticulocytes. This reticular structure is usually lost before the cells enter circulation as mature erythrocytes. The proper formation of erythrocytes depends primarily on nutrition, with protein, iron, and copper essential for the formation of hemoglobin, and vitamin B12 and folic acid necessary for DNA synthesis in stem cells of the red bone marrow.

As erythrocytes age and become fragile, they are removed from circulation by macrophages in the liver, spleen, and red bone marrow. The protein and iron of hemoglobin are reused; iron may be stored in the liver until needed for the production of new erythrocytes in the bone marrow. The heme portion of the hemoglobin is converted to bilirubin, which is excreted in bile as one of the bile pigments.

Varieties

On microscopic examination, erythrocytes may reveal variations in the following respects: size (anisocytosis), shape (poikilocytosis), staining reaction (achromia, hypochromia, hyperchromia, polychromatophilia), structure (possession of bodies such as Cabot's rings, Howell-Jolly bodies, Heinz bodies; parasites such as malaria; a reticular network; or nuclei), and number (anemia, polycythemia).

achromatic erythrocyte

An erythrocyte from which the hemoglobin has been dissolved; a colorless cell.

basophilic erythrocyte

An erythrocyte in which cytoplasm stains blue. The staining may be diffuse (material uniformly distributed) or punctate (material appearing as pinpoint dots).

crenated erythrocyte

An erythrocyte with a serrated or indented edge, usually the result of withdrawal of water from the cell, as occurs when cells are placed in hypertonic solutions.

immature erythrocyte

Any incompletely developed erythrocyte.

orthochromatic erythrocyte

An erythrocyte that stains with acid stains only, the cytoplasm appearing pink.

polychromatic erythrocyte

An erythrocyte that does not stain uniformly.

erythrocyte

A red blood cell. ‘Erythro’ means ‘red’, and ‘cyte’ means ‘cell’. Erythrocytes are flattened discs, slightly hollowed on each side (biconcave) and about 7 thousandths of a millimetre in diameter. They contain HAEMOGLOBIN and their main function is to transport OXYGEN from the lungs to the tissues.
ErythrocyteFig. 154 Erythrocyte . (a) Surface view. (b) Vertical section.

erythrocyte or red blood cell (RBC)

a vertebrate cell that contains HAEMOGLOBIN pigment for oxygen transport from lungs to tissues and carries small amounts of carbon dioxide as HCO3 - from tissues to lungs (see also CHLORIDE SHIFT). Unlike other vertebrate cells, mammalian RBCs are non-nucleated and have definite biconcave shape. Compare LEUCOCYTE.

Erythrocyte

The name for red blood cells or red blood corpuscles. These components of the blood are responsible for carrying oxygen to tissues and removing carbon dioxide from tissues.Mentioned in: Hemolytic Anemia

e·ryth·ro·cyte

(ĕ-rith'rŏ-sīt) A mature red blood cell.
Synonym(s): hemacyte, red blood cell, red cell, red corpuscle.
[erythro- + G. kytos, cell]

Patient discussion about erythrocyte

Q. what is a normal red blood cell count for breast cancer after operation A. i know that the normal count is between 4.2 to 5.9 million cells/cmm. if you have anything else- i think this question should be to the Doctor...cause even if someone here will tell you it's ok that it's a bit low- the Doctor should know that and he has your chart with all your medical information. there for i would give him a phone call to ask if it's o.k. - unless you are in the normal average i told you, then you shouldn't worry about it.

More discussions about erythrocyte
">erythrocyte cells" href="javascript:eml2('davisTab', 'e30.jpg')">ERYTHROCYTES: Note the different size and shape of the red blood cellsA blood cell (i.e., a circulating cell that contains hemoglobin and carries oxygen to tissue). Each erythrocyte is a nonnucleated, biconcave disk averaging 7.7 µm in diameter. An erythrocyte has a typical cell membrane and an internal stroma made of lipids and proteins to which more than 200 million molecules of hemoglobin are attached. The total surface area of the erythrocytes of an average adult is 3820 sq m, or about 2000 times more than the external total body surface area. Synonym: red blood cell; red blood corpuscle; red cell; red corpuscle See: illustration

Number

In a normal person, the number of erythrocytes averages about 5,000,000/µL (5,500,000 for men and 4,500,000 for women). The total number in an average-sized person is about 35 trillion. The number per µL varies with age (higher in infants), time of day (lower during sleep), activity and environmental temperature (increasing with both), and altitude. People living at altitudes of 10,000 ft (3048 m) or more may have an erythrocyte count of 8,000,000/µL or more.

If a person has a normal blood volume of 5 L (70 mL/ kg of body weight) and 5,000,000 erythrocytes per µL of blood, and the erythrocytes live 120 days, the red bone marrow must produce 2,400,000 erythrocytes per second to maintain this erythrocyte count.

Physiology

The primary function of erythrocytes is to carry oxygen. The hemoglobin also contributes to the acid-base balance of the blood by acting as a buffer for the transport of carbon dioxide in the plasma as bicarbonate ions.

Development

Erythrocyte formation (erythropoiesis) in adults takes place in the bone marrow, principally in the vertebrae, ribs, sternum, hip bone, diploë of cranial bones, and proximal ends of the humerus and femur. erythrocytes arise from large nucleated stem cells (promegaloblasts), which give rise to pronormoblasts, in which hemoglobin appears. These become normoblasts, which extrude their nuclei. erythrocytes at this stage possess a fine reticular network and are known as reticulocytes. This reticular structure is usually lost before the cells enter circulation as mature erythrocytes. The proper formation of erythrocytes depends primarily on nutrition, with protein, iron, and copper essential for the formation of hemoglobin, and vitamin B12 and folic acid necessary for DNA synthesis in stem cells of the red bone marrow.

As erythrocytes age and become fragile, they are removed from circulation by macrophages in the liver, spleen, and red bone marrow. The protein and iron of hemoglobin are reused; iron may be stored in the liver until needed for the production of new erythrocytes in the bone marrow. The heme portion of the hemoglobin is converted to bilirubin, which is excreted in bile as one of the bile pigments.

Varieties

On microscopic examination, erythrocytes may reveal variations in the following respects: size (anisocytosis), shape (poikilocytosis), staining reaction (achromia, hypochromia, hyperchromia, polychromatophilia), structure (possession of bodies such as Cabot's rings, Howell-Jolly bodies, Heinz bodies; parasites such as malaria; a reticular network; or nuclei), and number (anemia, polycythemia).

achromatic erythrocyte

An erythrocyte from which the hemoglobin has been dissolved; a colorless cell.

basophilic erythrocyte

An erythrocyte in which cytoplasm stains blue. The staining may be diffuse (material uniformly distributed) or punctate (material appearing as pinpoint dots).

crenated erythrocyte

An erythrocyte with a serrated or indented edge, usually the result of withdrawal of water from the cell, as occurs when cells are placed in hypertonic solutions.

immature erythrocyte

Any incompletely developed erythrocyte.

orthochromatic erythrocyte

An erythrocyte that stains with acid stains only, the cytoplasm appearing pink.

polychromatic erythrocyte

An erythrocyte that does not stain uniformly.

erythrocyte

A red blood cell. ‘Erythro’ means ‘red’, and ‘cyte’ means ‘cell’. Erythrocytes are flattened discs, slightly hollowed on each side (biconcave) and about 7 thousandths of a millimetre in diameter. They contain HAEMOGLOBIN and their main function is to transport OXYGEN from the lungs to the tissues.
ErythrocyteFig. 154 Erythrocyte . (a) Surface view. (b) Vertical section.

erythrocyte or red blood cell (RBC)

a vertebrate cell that contains HAEMOGLOBIN pigment for oxygen transport from lungs to tissues and carries small amounts of carbon dioxide as HCO3 - from tissues to lungs (see also CHLORIDE SHIFT). Unlike other vertebrate cells, mammalian RBCs are non-nucleated and have definite biconcave shape. Compare LEUCOCYTE.

Erythrocyte

The name for red blood cells or red blood corpuscles. These components of the blood are responsible for carrying oxygen to tissues and removing carbon dioxide from tissues.Mentioned in: Hemolytic Anemia

e·ryth·ro·cyte

(ĕ-rith'rŏ-sīt) A mature red blood cell.
Synonym(s): hemacyte, red blood cell, red cell, red corpuscle.
[erythro- + G. kytos, cell]

Patient discussion about erythrocyte

Q. what is a normal red blood cell count for breast cancer after operation A. i know that the normal count is between 4.2 to 5.9 million cells/cmm. if you have anything else- i think this question should be to the Doctor...cause even if someone here will tell you it's ok that it's a bit low- the Doctor should know that and he has your chart with all your medical information. there for i would give him a phone call to ask if it's o.k. - unless you are in the normal average i told you, then you shouldn't worry about it.

More discussions about erythrocyte
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