Control of Breathing Flashcards
What is the role of the central pattern generator?
It sends signals to the motor neurons of respiration to trigger regular breathing
In what part of the brain is the central pattern generator?
Though there is not a known exact location, it is certainly in the medulla oblongata
What would the consequence be if the medulla and spinal cord were severed from each other?
Primary muscles of inspiration would no longer function though secondary muscles of inspiration would still work
What would be the consequence on respiration if the pons and medulla were severed from each other?
Integrated respiration would continue
What are the two functions of the secondary muscles of respiration?
1) Help in the bellows function by changing the shape of the rib cage
2) Open the pharyngeal and laryngeal airways
What are the roles of the dorsal respiratory group?
1) integrate incoming sensation from the lungs and chemoreceptors via CN IX and X
2) trigger responses via premotor neurons and interneurons
- –note: no direct motor neurons exist in this group!–
What are the roles of the ventral respiratory group?
1) It contains expiratory and inspiratory neurons
2) It contains motor neurons that innervate accessory muscles of respiration
- -note: no direct sensation information except from the DRG!–
Where are peripheral chemoreceptors located and what blood component do they normally sense?
They are in the carotid and aortic bodies and sense pO2
How can the autonomic nervous system affect the role of peripheral chemoreceptors?
The sympathetic nervous system can reduce blood flow to the receptors; since they have a high metabolic rate, they will sense the decrease in local blood oxygen and prompt increased ventilation
How does peripheral chemoreception work?
As O2 drops or CO2 increases, the receptors will generate an action potential that sends a signal back to the brain
What are the three main roles of the central chemoreceptors?
1) Provide tonic regulation of breathing
2) Sense changes in carbon dioxide in the blood
3) Sense changes in pH as a result of changes in bicarbonate in the blood
Why do the central chemoreceptors respond less quickly to other triggers of pH change?
Most ions struggle to cross the blood-brain barrier
What is the role of slow pulmonary stretch receptors?
They detect when the lung is reaching its capacity and send triggers to the brain to stop inspiration and to initiate expiration
What is the role of fast pulmonary stretch receptors?
They detect irritants to the lungs, both inhaled and endogenously generated
What is the role of C-fibers?
They aim to prevent foreign particles from entering deep lung tissues by promoting bronchoconstriction, mucus production, and rapid breathing
