1. The circulatory system refers to our breath.

2. Humans have only five senses.

3. In humans, the optic nerve leads to the brain.

4. The resting heart rate of an average human adult is 120 beats per minute.

5. Insulin regulates the level of sugar in the body.

6. The circulatory system in humans has two parts.

7. The pancreas produces insulin.

8. Most body heat is lost through the head.

9. We use only 10 percent of our brains.

10. Skin serves no real purpose.