9. Respiratory Control Flashcards
What is the normal PaO2 and PaCO2 in arterial blood?
PaO2 = 95 mm Hg PaCO2 = 40 mm Hg
What are the four main respiratory centers in the brainstem?
Dorsal respiratory group (DRG)
Ventral respiratory group (VRG)
Pontine respiratory group (PRG)
Botzinger complex (and Pre-Botzinger complex)
What respiratory center generates the timing (frequency) of the respiratory rhythm?
Pre-Botzinger complex
What is apneusis? A lesion of what respiratory center can cause it?
Failure to turn inspiration off (stuck in inspiration)
Lesions in PRG can cause it
What respiratory centers control the depth (pattern) of breathing?
DRG and VRG
What neurons make up 95% of the DRG?
Premotor neurons to the phrenic nerve
What is the difference between the rostral and caudal regions of the VRG?
Rostral: premotor for muscles of inspiration
Caudal: premotor for muscles of expiration
What are the main differences between apneusis and apnea?
Apneusis: maintained inspiratory discharge. Caused by pontine damage.
Apnea: absence of respiratory effort (no inspiration). Caused by medullary or spinal damage.
How are central chemoreceptors activated?
CO2 crosses BBB. CO2 converted to H+ and HCO3 via carbonic anhydrase and water. H+ then directly stimulates the central chemoreceptors.
What is the main neurotransmitter used by the carotid body?
Dopamine
What is the carotid body sensitive to changes to?
O2, CO2, and H+
What is the role of slowly-adapting pulmonary stretch receptors?
Sensitive to stretch of airways. If activated, they inhibit inspiration and prolong expiration. Most important in controlling respiration in infants and adults during exercise.
What is the role of rapidly adapting pulmonary stretch receptors?
Sensitive to irritation and foreign bodies in airway. If activated, triggers the cough reflex.
What is the role of juxtacapillary (J) receptors?
Sensitive to pulmonary edema in alveolar space. If activated, triggers the cough reflex and tachypnea.
