Changing Patterns of Flow

Circulatory patterns within a hemocoel are complex. Pathways for flow vary for many reasons including volume of hemolymph in the cavity, what enters from the alimentary canal, the bee's state of hydration, temperature, level of activity and developmental stage, to mention a few. For example, as muscles in the walls of the heart and dorsal vessel propel blood forward through the aorta, at the same time hemolymph leaves the dorsal sinus to enter the ostia of the heart. This forward flow in the vessel drags hemolymph in the dorsal sinus forward. At the same time, hemolymph moving backwards from the head courses through the visceral and ventral sinuses. Lateral and medial currents interconnect these sinuses and also pass around the alimentary canal as flows mingle over the insides of the external boundaries of the hemocoel. At the same time, some hemolymph, assisted by pulsatile organs and movements of the body, enters and leaves the wings and appendages.

0 0

Post a comment