N: 1. – red (adj): Old English read “red,” from Proto-Germanic *rauthan (source also of Old Norse rauðr, Danish rød, Old Saxon rod, Old Frisian rad, Middle Dutch root, Dutch rood, German rot, Gothic rauþs), from PIE root *reudh- “red, ruddy,” the only color for which a definite common PIE root word has been found. As a noun from mid-13c.
– blood (n): Old English blod “blood, fluid which circulates in the arteries and veins,” from Proto-Germanic *blodam “blood” (source also of Old Frisian blod, Old Saxon blôd, Old Norse bloð, Middle Dutch bloet, Dutch bloed, Old High German bluot, German Blut, Gothic bloþ), according to some sources from PIE *bhlo-to-, perhaps meaning “to swell, gush, spurt,” or “that which bursts out” (compare Gothic bloþ “blood,” bloma “flower”), from suffixed form of root *bhel- (3) “to thrive, bloom.” But Boutkan finds no certain IE etymology and assumes a non-IE origin.
– cell (n): early 12c., “small monastery, subordinate monastery” (from Medieval Latin in this sense), later “small room for a monk or a nun in a monastic establishment; a hermit’s dwelling” (c. 1300), from Latin cella “small room, store room, hut,” related to Latin celare “to hide, conceal,” from PIE root *kel- (1) “to cover, conceal, save.”
From “monastic room” the sense was extended to “prison room” (1722). The word was used in 14c., figuratively, of brain “compartments” as the abode of some faculty; it was used in biology by 17c. of various cavities (wood structure, segments of fruit, bee combs), gradually focusing to the modern sense of “basic structure of all living organisms” (which Oxford English Dictionary dates to 1845).
Electric battery sense is from 1828, based on the “compartments” in very early types. Meaning “small group of people working within a larger organization” is from 1925. Cell-body is from 1851, cell-division from 1846, cell-membrane from 1837 (but cellular membrane is 1732), cell wall from 1842.
2. A blood cell containing the red pigment haemoglobin, the principal function of which is the transport of oxygen.
3. Red blood cell, also called erythrocyte, cellular component of blood, millions of which in the circulation of vertebrates give the blood its characteristic colour and carry oxygen from the lungs to the tissues. The mature human red blood cell is small, round, and biconcave; it appears dumbbell-shaped in profile. The cell is flexible and assumes a bell shape as it passes through extremely small blood vessels. It is covered with a membrane composed of lipids and proteins, lacks a nucleus, and contains hemoglobin—a red, iron-rich protein that binds oxygen.
4. The function of the red cell and its hemoglobin is to carry oxygen from the lungs or gills to all the body tissues and to carry carbon dioxide, a waste product of metabolism, to the lungs, where it is excreted. In invertebrates, oxygen-carrying pigment is carried free in the plasma; its concentration in red cells in vertebrates, so that oxygen and carbon dioxide are exchanged as gases, is more efficient and represents an important evolutionary development. The mammalian red cell is further adapted by lacking a nucleus—the amount of oxygen required by the cell for its own metabolism is thus very low, and most oxygen carried can be freed into the tissues. The biconcave shape of the cell allows oxygen exchange at a constant rate over the largest possible area.
S: 1. OED – https://bit.ly/315GVjr (last access: last access: 8 October 2019). 2. TERMIUM PLUS – https://bit.ly/2IJfR3f (last access: last access: 8 October 2019). 3 & 4. EncBrit – https://bit.ly/2qWggc1 (last access: last access: 8 October 2019).
SYN: erythrocyte, RBC, red cell, red blood corpuscle, red corpuscle. (depending on context)
S: GDT – https://bit.ly/2M8upvb (last access: 8 October 2019)