Biology and Human Anatomy
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ArticleDoes your heart stop when you sneeze? No, your heart does not stop when you sneeze. Edison Kinetoscopic record of a sneeze. Print shows a man, Edison engineer Fred Ott, sneezing. The accompanying Harper’s Weekly article describes the image...
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ArticleWhat are stem cells? Stem cells are the cells that have an ability to become various types of cells. They are present both during embryonic development (embryonic stem cells) and in the adult body (adult stem...
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ArticleWhat causes the noise when you crack a joint? Escaping gases, movement and rough surfaces. Thomas Gemini. Compendiosa totius Anatomie Delineatio… (Compendium of all anatomy delineated…). London: John Herford, 1545. Rosenwald Collection, Rare Book and Special Collections Division, Library of Congress....
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ArticleWhat is the strongest muscle in the human body? There is no one answer for this question since there are different ways to measure strength. There is absolute strength (maximum force), dynamic strength (repeated motions), elastic strength (exert force quickly), and...
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ArticleWhy do fingers and toes wrinkle in the bathtub? The outermost layer of the skin swells when it absorbs water. It is tightly attached to the skin underneath, so it compensates for the increased area by wrinkling. However, new research is...
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ArticleWhy do we yawn? Yawning might serve a social function (to communicate boredom) and a physiological function (regulation of body state). La Paresse: Caricature of sleep or boredom. Louis Le?opold Boilly, 1824. National Library of Medicine...
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ArticleWhy does hair turn gray? It is well known that gray hair results from a reduction of pigment, while white hair has no pigment, but why this happens remains somewhat of a mystery. Ayer’s hair vigor for...
