1. for each of the following cases. check the column appropriate to your observations on the operation of the model lung Diaphragm pushed up Dlaphragm pulled down Change Increased Decreased Increased Decreased In internal volume of the bell jar Sthoracc cavity in internal pressure of the bel jar In the sae of the balloons ungo 2. Base your answers to the folowing on your observations in question 1. Under what internal conditions of the thoracic cavity does ar tend to flow into the lngs? Under what internal conditions of the thoracic cavity does air tend to fow out of the lungs? Explain why this IS S0. 3. Activation of the diaphragm and the external intercostal muscles begins the inspiratory process. What effect does contraction of these musces have on thoracic volume, and how is this accomplished? 4. What was the approximate increase in diameter of chest circumference during a quiet inspiration? cm During forced inspiration? Cm 5. What temporary physiological advantage is created by the substantial increase in chest circumference during forced inspiration?