Question

On contraction of alary muscles, the size of pericardial sinus

• A. Increases
• B. Decreases
• C. Remains same
• D. There is no relation between the two

Answer 1

The correct option is A Increases

The alary muscles are twelve pairs whose alternate contractions and relaxations cause the dorsal diaphragm ventricular to rise and fall and so results in the blood to flow from perivisceral sinus to pericardial sinus and finally into the heart as it beats. On contractions of alary muscles, the size of pericardial sinus increases.

So the correct answer is 'Increases'.