Investitigation of Veins and arteries. Research topic: the elasticity of cows vein and aorta hung with different masses.

Materials and apparatus:

• Cow’s vein
• Cow’s aorta
• 1 Stand and clamp
• 1 Paper clips
• 1 Ruler (+/-0.5mm)
• 10 Weights of 100 grams each

Method:

1. Cut out a ring of 3mm from the aorta and another from vena cava
2. Use the clip to hang the aorta ring on the stand
3. Measure the length of the aorta ring
4. Add a weight of 100 grams to the aorta ring
5. Measure the length of the aorta ring
6. Repeat step 4 and 5 for 9 times (the maximum mass added is 1000 grams)
7. Repeat all the steps with vena cava
8. Record the result.

Raw data collecting

Data processing:

The length of both vein and artery was increasing very clearly at the beginning duo to the increase of mass added. This is because the blood vessels has reached its limitation and hence has stopped increasing and started leveling off. Although there are some strange signs with length of group 1 and group 5, the trend was still increasing at the beginning and kept constant at the end.

Quanlitative data:

As we can see, the percentage increase in length of both vein and artery is increasing at the beginning but keep constant at the end. This is because the blood vessels have reached their limitations.

Compare the two length increase in vein and artery, we can see that the artery increase in length less than the vein. The reason for this is the artery have thicker walls and harder in order to complete its mission as the carrier of blood to the whole body.