Which of the following statement is correct with respect to alary muscles in cockroach?

Contraction and relaxation of alary muscles help in blood circulation. When alary muscles contract, the pericardial sinus increases and creates low pressure for the flow of haemolymph from perineural and perivisceral sinuses. When they relax, the haemolymph from pericardial sinus enters into the heart by the opening of ostia.