Search results
Results from the WOW.Com Content Network
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.
Diagram of the frog heart preparation used by Loewi. Vagus nerve stimulation slows heart rate while accelerator (sympathetic) nerve stimulation speeds up heart rate. Vagusstoff (literally translated from German as "Vagus Substance") refers to the substance released by stimulation of the vagus nerve which causes a reduction in the heart rate.
In order to relate the work of the heart to skeletal muscle mechanics, Frank observed changes in diastolic pressure with varying volumes of the frog ventricle. His data was analyzed on a pressure-volume diagram, which resulted in his description of peak isovolumic pressure and its effects on ventricular volume. [5]
In 1852, H. F. Stannius used a frog's heart in a procedure called a Stannius ligature to demonstrate the ventricle and atria beat independently of each other and at different rates. [224] The African clawed frog or platanna (Xenopus laevis) was first widely used in laboratories in pregnancy tests in the first half of the 20th century.
The early bulbus cordis is formed by the fifth week of development. [4] The truncus arteriosus is derived from it later. [2]The adjacent walls of the bulbus cordis and ventricle approximate, fuse, and finally disappear, and the bulbus cordis now communicates freely with the right ventricle, while the junction of the bulbus with the truncus arteriosus is brought directly ventral to and applied ...
The trabeculae carneae and the papillary muscles make up a significant percentage of the ventricular mass in the heart (12-17% in normal human adult hearts), and are correlated with ventricular end diastolic volume. [5] Trabeculae ratios of capillary-to myocyte differ between the walls of the right and left ventricle.
Tesla CEO and “first buddy” Elon Musk was hit with a wave of immediate outrage online and on cable news after he made a salute that many felt was fascist during his speech at the Capitol One ...
Diagram of the human heart, created by Wapcaplet in Sodipodi. Cropped by ~~~ to remove white space (this cropping is not the same as Wapcaplet's original crop). == See also == * Image:Diagram of the human heart.svg - original