Conus Arteriosus

The conus arteriosus aids the shark in achieving its size despite its basic closed circulatory system by attenuating the initial pressure over a longer period of time. It does this primarily via the tissue having a relatively high elasticity. By expanding in response to pressure, it increases the diameter of the artery, which inversely affects the pressure of the blood as the blood moves through it. It then returns to its initial, unexpanded state, generating pressure and moving blood to the gills. The blood is directed towards the gills during this contraction by the utilization of unidirectional valves. The sum total of the pressure of the blood after the conus arteriosus, when compared to the pressure of blood leaving the ventricle due to contraction, is diminished only by distance travelled.


In this image, 5 shows the conus arteriosus and 4 illustrates
the series of valves within the conus arteriosus.


The elasticity of the conus arteriosus does not reduce the net force driving the blood from a pumping of the heart. This acts as a form of conservation of elastic energy where the circumference of the conus arteriosis at any one point can be used to find the resting position and the difference from the initial position in conjunction with an associated spring coefficient to find the associated potential energy. This can be used to further determine the pressure and subsequent velocity of the blood.


U = ½ k (x_f - x_i)²