Regulation of respiration Flashcards
What is the strongest factor influencing ventilation?
Arterial pCO2
Changes in arterial pCO2 trigger which chemoreceptors?
Peripheral and central
How do the effects of arterial pCO2 differ between peripheral and central chemoreceptors?
Stimulation of peripheral chemoreceptors is 5x as fast
How does low pO2 increase alveolar ventilation rate independently of pCO2?
Peripheral chemoreceptor system
Peripheral chemoreceptors are important for detecting what changes?
Changes in blood pO2
Where do the afferent nerve fibers from the carotid bodies go?
Hering’s nerves –> CN IX –> dorsal respiratory area of medulla
Where do the afferent nerve fibers from the aortic bodies go?
Vagus nerves –> dorsal respiratory area of medulla
Which area detects changes in either pCO2 or [H+]?
Central chemoreceptors (chemosensitive area)
What is the termination point for CN IX and X?
Nucleus of the tractus solitarius (ventral and dorsal respiratory groups)
What is the function of the pre-Botzinger complex?
Produces rhythmic discharges (pacemaker)
What is the function of the dorsal respiratory group?
Sends out repetitive bursts of INSPIRATORY neuronal action (inspiratory ramp signals)
What is the function of the pneumotaxic center?
Controls RATE and DEPTH of breathing, as well as switch-off of inspiratory ramp
What is the role of the ventral respiratory group?
- Inactive during normal quiet respiration 2. During high demand signals spill over from DRG to VRG 3. VRG contributes to both inspiration and expiration - especially important in providing strong expiratory signals to abdominal muscles during heavy expiration
Where are pneumotaxic center signals sent?
Inspiratory area
What are J receptors?
- Sensory nerve endings in alveolar walls in juxtaposition to pulmonary capillaries 2. Stimulated when pulmonary capillaries become engorged with blood or during pulmonary edema 3. Activation causes sensation of dyspnea
