Control Of The Respiratory System Flashcards
What are the lungs innervated by?
Symp: thoracic 1-4
Para: cranial nerve 5
What are the brain centres for respiration?
The main respiratory centre in the medulla
The secondary respiratory centre in the pons
The hypothal and lambic system have excitatory and inhib effects on the resp centres
Under vol control from cerebral cortex
What are the respiratory centres and their functions?
Dorsal respiratory group (inspiratory): - generates basic rhythm of breathing
Ventral respiratory group (expiratory area): - forced breathing
Botzinger complex: - generation of respiratory rhythm (pacemaker activity)
Pontine respiratory group (apneistic centre)
What happens if you sever the medulla?
You stop breathing
What is the function of the medulla?
Controls inspiration and expiration
What is the function of the dorsal respiratory group?
In the medulla
Generates basic rhythm
Impulses from group increases vol during inspiration
Ramp sig spontaneously cases for a few seconds and starts again
What is the function of the ventral respiratory group?
In medulla, inactive in normal quiet breathing
Heavier breathing RAMP sig such spill over act the neurones in the VRG
Stuns contract of muscles involved in forced expiration
Deeper expiration
What chemical factors affect breathing?
Chemoreceptors respond to pH
and baroreceptors respond to partial pressures of O2 and CO2
Where are chemoreceptors located? (Central and peripheral)
Bilaterally and ventrally in the chemosensitive area of the medulla
Peripheral found in carotid and aortic bodies
What partial pressures of O2 and CO2 affect respiration?
40% drop in pO2 will increase inspiration by 50%
A 10% rise in pCO2 will double resp rate
What innervates the diaphragm?
The phrenic nerve
What innervates the intercostal muscles?
The intercostal nerves
Where do the main innervation of the respiratory system originate from?
Spinal cord T1-11
Which adr receps are in the lungs?
B2
What is the function of b2-adr receps?
Causes bronchodilation
