Question

In the blood circulation of Pheretima, the blood collected by lateral oesophageal blood vessel flows into supra oesophageal blood vessels through

• A. Lateral oesophageal hearts and ring vessels
• B. Anterior loops and ring vessels
• C. Lateral hearts and commissural blood vessels
• D. Lateral hearts and anterior loops

Answer 1

Answer: (A)

Lateral oesophageal hearts and ring vessels

The hearts in the 12th and 13th segments are called lateral oesophageal hearts. There are also two pairs of non-pulsatile loops in segments 10 and 11, which connects the supra-oesophageal vessel to the lateral oesophageal vessels.
The sub-neural vessel receives blood via the lateral-oesophageal vessels from the anterior region and supplies it to the dorsal vessel through the commissural vessels. The lateral oesophageal vessels also send blood through the anterior loops to the supra-oesophageal vessel, which then passes it through the lateral oesophageal hearts to the ventral vessels.
ring vessels are the vessels present in the wall of the gut. They connect the lateral oesophageal vessels to the supra-oesophageal vessels. There are 12 vessels in each segment.

Thus, the correct answer is option (A).