Puzzels
Kan iemand mij vertellen over welke 'negative charges' ze het hebben? Deze worden niet genoemd in chapter 5. Het enige wat ik weet is dat na depolarisatie kalium ionen uit de cel stromen waardoor het binnen de cel negatiever wordt en doordat natrium ionen vanuit buiten naar binnen stromen wordt het buiten negatiever. Van negatieve dingen die naar buiten stromen heb ik nog nooit gehoord.
Recording Electrical Potentials from a
Partially Depolarized Mass of
Syncytial Cardiac Muscle
Instantaneous potentials develop on the surface of a cardiac
muscle mass that has been depolarized in its center.
Figure 11–4 shows a syncytial mass of cardiac muscle
that has been stimulated at its centralmost point.Before stimulation, all the exteriors of the muscle cells
had been positive and the interiors negative. For
reasons presented in Chapter 5 in the discussion of
membrane potentials, as soon as an area of cardiac
syncytium becomes depolarized, negative charges leak
to the outsides of the depolarized muscle fibers,
making this part of the surface electronegative, as represented
by the negative signs in Figure 11–4. The
remaining surface of the heart, which is still polarized,
is represented by the positive signs.Therefore, a meter
connected with its negative terminal on the area of
depolarization and its positive terminal on one of the
still-polarized areas, as shown to the right in the figure,
records positively.
Weet iemand waar zij het over hebben?
Bij voorbaat dank.
