Top Posters
Since Sunday
c
5
j
5
a
5
L
5
f
5
j
5
D
4
k
4
y
4
t
4
h
4
l
4
SlideshowReport

A closed circulatory system.

Description
In closed systems, such as that of the earthworm, blood remains in vessels or hearts and recirculates without emptying into the body cavity. The arrows indicate the direction of blood flow.
Related Images
Add Comment
Explore
Post your homework questions and get free online help from our incredible volunteers
  909 People Browsing
 141 Signed Up Today
Your Opinion
What's your favorite funny biology word?
Votes: 335

Previous poll results: How often do you eat-out per week?