Respiratory system

This patient has a normal respiratory system.

• You can control the composition of inspired air by dragging the sliders for Atmospheric CO2 and Atmospheric O2.
• The air pressure can be altered by dragging Barometric pressure.
• You can induce hyperventilation by dragging the slider for Hyperventilate to the right, and hypoventilation by dragging the same slider to the left. When the slider is set to 0, ventilation rate is controlled automatically.
• To see the effects of long-term hypoxia, decrease the Atmospheric O2 to 12%, and set the Time compression slider at the top of the screen to 1 hour per second.
• To see what happens in the case of respiratory arrest, first set the Time compression slider to Real time (far left), then turn on Breath Holding by clicking on the tick. To allow the patient to breathe again, click again on the tick.

If you want to view the partial pressures in kiloPascals rather than mmHg, select Tools/Options/Override internal units. A diagram of the current gas exchange is given under Tools/Examine patient/Gases diagram, and skin colour can also be viewed from here.

The basic equations of the system are as follows: