SA node and AV node
i think it is 4 chambers in the Human Heart
The bird's heart has 4 chambers.
4 heart chambers
The sharks heart has two chambers.
There are 4 chambers to the heart.
no. the heart only has 4 chambers
Penguins have 4 chambers in their heart.
4 hobbits in the fellowship (Horse Isle) WiseLeadMare (dun/grey)
A cats heart has four chambers, like humans.
A sheep heart has four chambers.
There are 4 chambers in a bird's heart.
There are four chambers in a human heart.