Question

Which of the following structures are found in 7${}^{th}$ and 9${}^{th}$ segments of Pheretima?

• A. Pharyngeal nephridia
• B. Lateral hearts
• C. Spermatheca
• D. Lateral esophageal hearts

Answer 1

The correct option is B Lateral hearts

The heart is present in the segments 7, 9, 12 and 13. It contracts and relaxes to pump the blood all through the body. They pump blood from dorsal to ventral vessel. the flow of the blood is regulated by internal valves. Hearts of 7th and 9th segments connect dorsal and ventral vessels only and are called as lateral hearts, while those of 12 and 13 segments connect both dorsal and supro-oesophageal vessels with the ventral vessel and are called as latero-oesophageal hearts. So, the correct answer is option B.