Describe the structure of the heart and the path of blood circulation in a cockroach.

(N/A) $\rightarrow$ The heart of a cockroach consists of an elongated,muscular tube lying along the mid-dorsal line of the thorax and abdomen.
$\rightarrow$ It is differentiated into $13$ funnel-shaped chambers,each with a pair of ostia on either side,which allow blood to enter the heart from the sinuses.
$\rightarrow$ The blood (hemolymph) is pumped anteriorly from the heart into the sinuses by the rhythmic contraction of these chambers.
$\rightarrow$ The blood cells,or hemocytes,are of two types: small proleucocytes and large phagocytes.