part_of adult heart adult heart pulsatile region Bulbous thickened posterior region of the heart. This is the pulsatile region. The heart muscle is especially thickened here with bands of striated muscle oriented circularly. Constriction of the muscles in this region drives the hemolymph anteriorly. Fig. 11-1, in Biology of Ticks. TADS:0000150 TADS:0000150 default_namespace