Circulatory System

Question 1

[Point 1]

The main collection vessel is the _____

Answer 1

• median dorsal vessel (dorsal aorta)
• It runs above the alimentary canal from the pharynx to the anus.

Question 2

[Point 2]

Blood flows:

Answer 2

Blood flows forward or towards the anterior end of the worm in the dorsal aorta.

Question 3

[Point 3]

Main distribution vessel?

Answer 3

medial ventral vessel

Question 4

[Point 4]

There are ? pairs of _____

Answer 4

5 pairs of enlarged transverse vessels (hearts)

Question 5

[Point 5]

What are the enlarged tranverse vessels called? What do they do?

Answer 5

• aortic arches
• Connect dorsal and ventral vessels.
• Force blood through ventral vessels.

Question 6

[Point 6]

Blood flows through:

Answer 6

aortic arches down to the ventral vessel & then towards the posterior end of the worm.