The Heart - Biofluidmechanics: An Introduction to Fluid Mechanics Macrocirculation and Microcirculation - page 102

FIGURE 4.3 Comparison of the
action potentials in nervous tissue and
cardiac tissue. There is a significant
elongation of depolarization phase in
cardiac tissues.

40

20

0

Nerve cell action potential

− 20

− 40

− 60

− 80

− 100
40

Purkinje fiber action potential

20

0

− 20

− 40

− 60

− 80

− 100

40
20

Ventricular muscle action potential

0
− 20
− 40
− 60
− 80
− 100

0 100 200 300

Time (ms)

400 500 600

blood to move between the respective atrium and ventricles. This pressure difference
exerts a force on the AV valves, causing them to open and allowing blood to move from
the atria into the ventricles. As the atria relax and the ventricles contract, the pressure gra-
dient reverses so that there is a higher pressure in the ventricles and a lower pressure in
the atria. This again exerts a force on the AV valves, causing them to close. As for the