Describe the structure and function of the heart in Periplaneta .

Explanation

Heart : The heart lies in the pericardial heamocoel or dorsal sinus . It is a long muscular , contractile tube found along the mid dorsal line , beneath the terga of the thorax and abdomen . It consists of 13 chambers . Every chamber opens into the other present in front of it Three of the thirteen chambers are situated in the thorax and ten anterior aorta At the posterior side of each chamber except the last , there is a pair of small apertures called Ostia one on each side Ostia have valves which allow the blood to pass only into heart from the dorsal sinus .