Answer:
0 to 145 degrees
Explanation:
The normal range of flexion and extension is from 0 to 145 degrees.
The body systems that help cells get the energy they need are the digestive system and circulatory system. The first system is the digestive system because when you eat food, your body breaks it down using the stomach and other different parts of the digestive system. The next one is the circulatory system because your blood carries the nutrients you acquired from food you digested to the cells throughout your body.
Answer:
The constriction causes the mercury column to break under tension, leaving a vacuum between the bottom of the column and that in the bulb, and the top of the column stays still at the position reached in the body - a "peak hold" system.