Hill
The 1922 Nobel Prize in Physiology or Medicine winner Archibald Hill proposed in 1924 that the heart was protected from anoxia in strenuous exercise by the existence of a governor.
the heart is able to regulate its output, to some extent, in accordance with the degree of saturation of the arterial blood … we suggest that, in the body (either in the heart muscle itself or in the nervous system), there is some mechanism which causes a slowing of the circulation as soon as a serious degree of unsaturation occurs, and vice versa. This mechanism would tend, to some degree, to act as a ‘governor’, maintaining a reasonably high degree of saturation of the blood: the breathing of a gas mixture rich in oxygen would produce a greater degree of saturation of the blood and so allow the output to increase until the ‘governor’ stopped it again. We realise the danger of a hypothesis partly suggested by teleological reasoning: in this case, however, we can see no other explanation of our experimental results pp. 161-163
This hypothesis was disregarded and further research upon exercise fatigue was modeled in terms of it being due to a mechanical failure of the exercising muscles ("peripheral muscle fatigue"). This failure was caused either by an inadequate oxygen supply to the exercising muscles, lactic acid buildup, or total energy depletion in the exhausted muscles.
Read more about this topic: Central Governor
Famous quotes containing the word hill:
“The Helicon of too many poets is not a hill crowned with sunshine and visited by the Muses and the Graces, but an old, mouldering house, full of gloom and haunted by ghosts.”
—Henry Wadsworth Longfellow (1807–1882)
“It breaks his heart that kings must murder still,
That all his hours of travail here for men
Seem yet in vain. And who will bring white peace
That he may sleep upon his hill again?”
—Vachel Lindsay (1879–1931)
“I got my first clear view of Ktaadn, on this excursion, from a hill about two miles northwest of Bangor, whither I went for this purpose. After this I was ready to return to Massachusetts.”
—Henry David Thoreau (1817–1862)