Control of Breathing Flashcards
Regular breathing is controlled by…
ANS without conscious effort
Respiratory control center is located in the…
medulla
Respiratory control center consists of 2 main clusters:
- dorsal respiratory group (DRG)
- ventral respiratory group (VRG)
DRG has neurons that are active during…
inspiration
VRG has neurons that mainly serve to…
switch off inspiration before expiration
- during exercise
Respiratory control center sets the…
central ventilation pattern
- controls rate and amplitude of ventilation
Normal control of breathing can be controlled by…
- input from higher centers
- chemical stimuli
How do higher centers control normal breathing?
- voluntary and emotion-driven changes in breathing
- most motor output through phrenic nerve
- gets input from proprioceptors
Examples of higher centers:
- cerebral cortex
- hypothalamus
- amygdala
- limbic system
- cerebellum
Examples of chemical stimuli:
drugs
- barbiturates
- general anesthesia
- narcotic pain relievers
How are chemical stimuli detected?
chemoreceptors (central and peripheral)
- activated by disruption of blood flow to medulla
Most common causes of activation of chemoreceptors:
- cerebral concussion
- cerebral edema
What are in the pons that control inspiration?
- pneumotaxic centers: inhibit inspiration (stimulated during exhalation)
- apneustic centers: stimulate inspiration (inhibited during exhalation)
Rate and depth of breathing are modified to meet…
metabolic needs
Increase in activity leads to…
increase in metabolic demand -> increase in ventilation
- increase in O2 delivered and CO2 eliminated
What can affect both rate and depth of breathing?
levels of O2, CO2, and H+
What is the most important regulator?
pCO2
- gets maintained at about 40 mmHg
Increase in pCO2 leads to…
increase in ventilation
What is hyperpnea?
increase in pCO2 will cause an increase in ventilation
- blows off excess pCO2
What is hyperventilation?
increase in ventilation that drives pCO2 down
- increases pH
- decreases ventilation
Central chemoreceptors are located in the…
medulla
Central chemoreceptors respond directly to _____ and indirectly to…
- directly: changes in pH of brainstem CSF
- indirectly: pCO2
How do central chemoreceptors detect CO2?
- CO2 crosses blood brain barrier
- gets converted and results in increase of H+
- decrease in pH and increase in pCO2
- firing rate of neurons increased
- increase in output to inspiratory muscles
Peripheral chemoreceptors are located in the…
aortic and carotid bodies
