A tadpole lives underwater at all times, so its circulatory system is not unlike the circulatory system of a fish. Unlike a frog, a tadpole has a two chambered heart (there is only one atrium and one ventricle). The blood travels through the body as follows: All the blood in the body moves to the atrium, then the heart relaxes and the blood moves to the ventricle. When the ventricle contracts, blood is forced into capillary networks of the gills, where the gas exchange occurs (carbon dioxide from blood cells are released, while oxygen diffuses into blood cells). Then the blood travels along capillary networks to supply the rest of the body with oxygenated blood. This process repeats. This system is called a single loop system because there is not a separate loop for the blood going from the gas exchange site to heart (or vice versa), and the blood going from the heart to the rest of the body (of vice versa). A frog has a double-loop circulatory system.
A frog has a three chambered heart. In this system, the right atrium contains de-oxygenated blood while the left atrium contains oxygenated blood. In this circulatory system, the frog has a double loop. The first loop carries blood from the lungs to heart (or vice versa) for gas exchange to take place while the second loop carries oxygenated blood to the rest of the body while taking the de-oxygenated blood away. The blood in both atria empty into the third chamber, the ventricle. The ventricle is divided into two narrow chambers to avoid mixing of blood. When the ventricle contracts, oxygenated blood is send through the carotid arteries to take blood to the head while the de-oxygenated blood is sent to the pulmocutaneous arteries to take blood to the gas exchange site (whether it be the lungs, the skin or the lining in the mouth). The blood that passes through the aortic arches are a mixture of oxygenated and de-oxygenated blood, but there is still enough oxygen supply for the rest of the body.
In conclusion to this system, the main differences between the circulatory systems are the different number of heart chambers and the different number of circulatory system loops.
Unfortunately, during the dissection we could not find the heart, but this is a diagram of the different chambers in a frog’s heart. We believe we couldn't find the heart because we did not cut high enough into the anterior end of the abdominal cavity. The link where the photo came from is shown below:
http://bioserv.fiu.edu/~biolab/labs/1011/Fall%202010/Documents%20on%20Website/supplemental_materials%20Fall%202010.htm
A frog has a three chambered heart. In this system, the right atrium contains de-oxygenated blood while the left atrium contains oxygenated blood. In this circulatory system, the frog has a double loop. The first loop carries blood from the lungs to heart (or vice versa) for gas exchange to take place while the second loop carries oxygenated blood to the rest of the body while taking the de-oxygenated blood away. The blood in both atria empty into the third chamber, the ventricle. The ventricle is divided into two narrow chambers to avoid mixing of blood. When the ventricle contracts, oxygenated blood is send through the carotid arteries to take blood to the head while the de-oxygenated blood is sent to the pulmocutaneous arteries to take blood to the gas exchange site (whether it be the lungs, the skin or the lining in the mouth). The blood that passes through the aortic arches are a mixture of oxygenated and de-oxygenated blood, but there is still enough oxygen supply for the rest of the body.
In conclusion to this system, the main differences between the circulatory systems are the different number of heart chambers and the different number of circulatory system loops.
Unfortunately, during the dissection we could not find the heart, but this is a diagram of the different chambers in a frog’s heart. We believe we couldn't find the heart because we did not cut high enough into the anterior end of the abdominal cavity. The link where the photo came from is shown below:
http://bioserv.fiu.edu/~biolab/labs/1011/Fall%202010/Documents%20on%20Website/supplemental_materials%20Fall%202010.htm