http___metro-portal.hr_ljudsko-tijelo-se-potpuno-obnovi-svake-sedme-godine-ne-bas_58763_1.xml
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It's a neat idea, and one that has caught the popular imagination. Here's how the story goes: Every seven years (or 10, depending on which story you hear) we become essentially new people, because in that time, every cell in your body has been replaced by a new cell. Don't you feel younger than you were seven years ago? It is true that individual cells have a finite life span, and when they die off they are replaced with new cells. As The New York Public Library's Science Desk Reference (Stonesong Press, 1995) notes, "There are between 50 and 75 trillion cells in the body.... Each type of cell has its own life span, and when a human dies it may take hours or day before all the cells in the body die." (Forensic investigators take advantage of this vaguely morbid fact when determining the cause and time of death of homicide victims.) Red blood cells live for about four months, while white blood cells live on average more than a year. Skin cells live about two or three weeks. Colon cells have it rough: They die off after about four days. Sperm cells have a life span of only about three days, while brain cells typically last an entire lifetime (neurons in the cerebral cortex, for example, are not replaced when they die). There's nothing special or significant about a seven-year cycle, since cells are dying and being replaced all the time. It's not clear where this myth began; perhaps some well-meaning but innumerate person simply added up the all the lifespans of the body's various types of cells and (mistakenly) assumed that all the cells are renewed after seven years.
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Ljudsko tijelo se potpuno obnovi svake sedme godine? Ne baš Istina je da pojedine stanice imaju ograničen životni vijek i da ih nakon odumiranja zamijene nove, ali to nema nikakve veze sa sedmogodišnjim ciklusom Popularno je mišljenje da se ljudsko tijelo svakih sedam godina potpuno obnovi (neki tvrde svakih deset godina). Drugim riječima, nakon tog vremenskog perioda po teoriji mi postajemo potpuno nova ljudska bića jer je svaku našu stanicu zamijenila nova. Recite nam, osjećate li se vi mlađima nego što ste bili prije sedam godina? Istina je da pojedine stanice imaju ograničen životni vijek i da ih nakon odumiranja zamijene nove. U enciklopediji The New York Public Library Science Desk Reference (Stonesong Press, 1995.) stoji: „U ljudskom tijelu se nalazi između 50 i 75 trilijuna stanica... Svaki tip stanice ima svoj životni vijek; kad čovjek umre, mogu proći sati ili dani dok sve stanice u tijelu ne umru." Forenzičari se služe upravo tom činjenicom kad određuju vrijeme i uzrok smrti žrtava ubojstva. Crvene krvne stanice žive oko četiri mjeseca, bijele pak više od godinu dana. Stanice kože žive dva do tri tjedna. Stanice debelog crijeva žive četiri dana. Spermiji oko tri dana, a moždane stanice čitav ljudski vijek s tim da se neuroni u cerebralnom korteksu uopće ne zamjenjuju novima nakon što odumru. Zaključak - nema ništa posebno oko sedmogodišnjeg ciklusa s obzirom da stanice odumiru i da se mijenjaju i obnavljaju neprestano. Nije poznato gdje je začet ovaj mit, ali očito je baš to - mit.