Question

In cockroach, the flow of haemolymph is

• A. Heart > ostia > perivisceral sinus > pericardial sinus > head sinuses > heart
• B. Heart > head sinuses > perivisceral sinus > ostia > pericardial sinus > heart
• C. Heart > pericardial sinus > head sinuses > perivisceral sinus > ostia > heart
• D. Heart > head sinuses > perivisceral sinus > pericardial sinus > ostia > heart.

Answer 1

The Correct Option is D

In cockroach, when the alary muscles contract, the dorsal diaphragm becomes flattened and the pericardial sinus is enlarged. Due to this, the blood flows from the perivisceral sinus to the pericardial sinus through the apertures present in the dorsal diaphragm. When the alary muscles relax, the dorsal diaphragm becomes arched so that the space of the pericardial sinus is reduced and the blood from the pericardial sinus is forced into the heart through the ostia. Thereafter the heart and the anterior arota contract peristaltically from behind to forward and thus the blood from the heart is circulated to the head sinuses and then it reaches the perivisceral and perineural sinuses.