Question

In cockroach the flow of haemolymph is

• A. heart $\to$ head haemocoei $\to$ perlvisceral sinus $\to$ pericardial sinus $\to$ ostia $\to$ heart
• B. heart $\to$ pericardial sinus $\to$ head haemocoei $\to$ perivisceral sinus $\to$ ostia $\to$ heart
• C. heart $\to$ head haemocoei $\to$ perivisceral sinus $\to$ ostia pericardial sinus $\to$ heart
• D. heart $\to$ ostia $\to$ perivisceral sinus $\to$ pericardial sinus $\to$ head haemocoei $\to$ heart

Answer 1

Answer: (A)

heart $\to$ head haemocoei $\to$ perlvisceral sinus $\to$ pericardial sinus $\to$ ostia $\to$ heart

Answer 2

In cockroach the flow of haemolymph is heart $\to$ head haemocoel $\to$ perivisceral sinus $\to$ pericardial sinus $\to$ ostia $\to$ heart. Heart in cockroach is neurogenic. Haemocoel (body cavity) is pervisceral cavity filled with colour less blood (haemolymph). When alary muscle contract the dorsal diaphragm became flat and pericardial increases. Blood from perivisceral sinus enter into pericardial sinus through pore of dorsal diaphragm become dome-shaped and blood from pericardial sinus is forced into the heart through valvular ostia then the heart and aorta contract peristaltically. Blood flow from posterior end to anterior end in heart and flow into head sinus through aorta.