Lecture 25: Central Control of Respiration Flashcards
(29 cards)
what is the primary regulator of ventilation?
PaCO2
what are the ventilation control elements?
central controllers
effectors (resp muscles)
sensors (central and peripheral)
what are the respiratory centers in the brainstem
medulla and pons
what are the breathing rhythm generators
rostral ventromedial neurons (pre-Botzinger complex) in the medulla
what are the inspiratory neurons of medulla
dorsal respiratory group
what are both inspiratory and expiratory neurons in medulla
ventral respiratory group
what two respiratory centers around found in the pons
pneumotaxic center (turns off inspiration of DRG)
Apneustic center (prolongs inspiration)
when is the dorsal respiratory group of medulla active
during eupnea (reg breathing)
inspiratory neurons
what does the dorsal respiratory group receive sensory input from
CN 9 and 10
when is the ventral respiratory group active
during forced expiration
what are the pontine centers
pneumotaxic center and apneustic center
what is the role of the penumotaxic center
- turns off inspiration at the DRG
- limits tidal volume
what is the role of the apneustic center
- apneusis = abnormal breathing pattern w/ prolonged inspiration
what is the cortical control of respiration responsible for
voluntary control of vocalizations, sighing, breath holding, etc
what is the limbic respiratory system responsible for
emotionally induced changes in ventilation
ex: fear
what is hypothalamic respiratory control responsible for
temperature control
ex: fever
what sensors are chemoreceptors, which are both chemo and mechanoreceptors
central sensors = chemoreceptors
peripheral sensors = chemo and mechanoreceptors
where are central chemoreceptors located
ventral surface of medulla
what stimulates central chemoreceptors
increased H+ in the CSF
H+ comes from CO2 diffusing across the BBB
Decreasing PaO2 causes an increased sensitivity of ventilation to ?
PaCO2
where are peripheral chemoreceptors found
carotid and aortic bodies
what do peripheral chemoreceptors mainly respond to
changes in PaO2
- also respond to changes of H+ (acidosis stimulates ventilation)
- have a weak response to CO2
what must PaO2 levels fall to before ventilation gets increased significantly
PaO2 must be below 60-70mmHg
name of cells in carotid bodies that respond to hypoxia, hypercapnia and low pH (part of peripheral chemoreceptor)
Glomus cells
