Respiratory rate

Factors which INCREASE respiratory rate

1. Hypoxemia
   * via: peripheral
2. Hypercapnoea
   * via: (mainly) central, peripheral
3. Acidosis
   * via: peripheral
4. Hyperthermia
   * via: peripheral, skin
5. Severe hypotension 
   * via: peripheral, arterial baroreceptor
6. Exercise 
   * via: joint/muscle receptor
7. Some chemicals and irritants
   * e.g. nicotine
   * via: peripheral chemoreceptors
8. Others
   * Pain
   * Emotion (e.g. anxiety)
   --> ????due to cortex and/or sympathetic nervous system stimulation

 

Other factors that affect RR but not part of control mechanism

Voluntary control (to limited extent)

Increased elastic recoil AND/OR lower airway resistance