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In 1852 H.F. Stannius experimented on the heart. By tying a ligature as a constriction between the sinus venosus and the atrium in the frog and also one around the atrioventricular groove, Stannius was able to demonstrate that the muscle tissues of the atria and ventricles have independent and spontaneous rhythms.
By the time Loewi began his experiments there was much discussion among scientists whether communication between nerves and muscles was chemical or electrical by nature. . Experiments by Luigi Galvani in the 18th century had demonstrated that electrical stimulation of the frog sciatic nerve resulted in twitching of the leg muscles, and from this he developed the concept of bioelectri
Loewi's famous experiment, published in 1921, largely answered this question. He dissected out of frogs two beating hearts: one with the vagus nerve which controls heart rate attached, the other heart on its own. Both hearts were bathed in a saline solution (i.e. Ringer's solution).
Ringer's solution is named after Sydney Ringer, who in 1882–1885 determined that a solution perfusing a frog's heart must contain sodium, potassium and calcium salts in a definite proportion if the heart is to be kept beating for long.
In his experiment, Loewi electrically stimulated the vagus nerve of a frog heart, which slowed the heart. Then he took the fluid from the heart and transferred it to a second frog heart without a vagus nerve. The second heart slowed without electrical stimulation.
The final suspect pleaded guilty in February of 1993 to hindering prosecution and received a sentence of 1 ½ to 4 ½ years in prison. He was also released to parole in 1996 and ultimately ...
Sen. Josh Hawley (R-Mo.) is asking the Senate Homeland Security Committee to call on Homeland Security Secretary Alejandro Mayorkas and FBI director Christopher Wray to testify after the New ...
Experiment De viribus electricitatis in motu musculari Late 1780s diagram of Galvani's experiment on frog legs. Luigi Galvani was born to Domenico Galvani and Barbara Caterina Foschi, in Bologna, then part of the Papal States. [6] The house in which he was born may still be seen on Via Marconi, 25, in the center of Bologna. [7]