1. Apnea is a temporary cessation of respiration.
2. Under normal physiological conditions, it occurs during deglutition and hyperventilation
3. Individuals can also voluntarily stop breathing as in the breath holding test
4. The different types of apnea are as follows:
- Deglutition apnea
- Voluntary apnea
- Vagal apnea
- Adrenaline apnea
- Hyperventilation apnea
5. Prolonged apnea results in the accumulation of CO2 in the blood which stimulates the respiratory center and breathing automatically commences.