How to Compare Hummingbirds to a Human Circulatory System

The pulse rate of hummingbirds can be around 600 beats per minute.

The circulatory system passes nutrients, gases and blood cells to and from cells in the body. This helps to stabilize body temperature and fight diseases. The system can be seen as a blood-distribution organ, and the blood in humans and birds never leaves the network of arteries, veins and capillaries. Birds have evolved to have large, powerful hearts. Smaller birds, such as hummingbirds, have a relatively large heart. The human heart weighs about 0.42 percent of the body's weight, while the some hummingbird species have hearts that amount to 2.4 percent of their body weight.

Instructions

1. Find pictures of the circulatory systems of humans and hummingbirds using online resources or reference books.

2. Peruse statistics related to the hearts of hummingbirds and humans. Look at the relative size and the number of heartbeats.

3. Compare the amount of blood the two hearts pump. A hummingbird's heart pumps more blood per unit.

4. Compare the shape and number of blood cells. The circulatory system carries blood. Hummingbirds have elliptical red blood cells, while human red blood cells have a round nucleus.

5. Compare pictures of the two hearts. Both hearts have four chambers. There are left and right ventricles and atria. The ventricles discharge blood and the atria receive blood.

6. Look at the aortic arch, which looks like an inverted U at the top of the heart.

7. Count the number of aortic arches. A human has four arches, while a hummingbird has three.

8. Look at where the aortas are leading. The human heart has a thoracic, abdominal, descending and ascending aorta. The hummingbirds' heart lacks the abdominal aorta.

9. Find the ductus caroticus on the hummingbird aorta. This part of the aorta disappears in early development in humans and other bird families, but hummingbirds continue to have it. This part transports blood to the abdominal aorta.

10. Compare all the differences and similarities between the human and the hummingbird circulatory system, and relate the differences to lifestyle adaptations. For example, examine the need for hummingbirds to meet the metabolic demands of flying around looking for food.

References

• Paul Noll.; Bird Circulatory System ; 2011
• People Eku Edu; Avian Circulatory System; 2011
• Rubythroat; Hummingbird Internal Anatomy & Physiology; 2011

Resources

• Teach PE; The Human Circulatory System ; 2011