Control of Ventilation Flashcards
What physical structures must be stimulated to cause inspiration?
Skeletal muscles (the diaphragm and external intercostals)
What innervates the thoracic-abdominal diaphragm?
The phrenic nerve
Which nerves innervate the external intercostal muscles?
The intercostal nerves
Where are the respiratory centres located?
In the pons and medulla of the brain
What can be said about the voluntary/involuntary nature of breathing?
It is mostly subconscious but can be subject to voluntary override
Severing of the spinal chord above the ventral rami of spinal nerves C3, 4 and 5 do what?
Kill you
C3, 4 and 5 keep your heart and lungs alive
The respiratory centres set an automatic rhythm of breathing by firing smooth and repetitive bursts of action potentials in which part of the respiratory centre?
The dorsal respiratory group
What four other aspects can modulate ventilation?
- Emotion (limbic system)
- Voluntary override
- Mechano-sensory input from thorax
- Chemical changes
What two types of chemoreceptor modulate ventilation?
Central and peripheral
What chemical route, central or peripheral, is the main control for ventilatory function?
Central
Central chemoreceptors response directly to what?
[H+] in cerebrospinal fluid
What does the [H+] indicate?
PCO2
Where are central chemoreceptors located?
Medulla of the brain
Where are peripheral chemoreceptors located in the body?
Carotid and aortic bodies
What do peripheral chemoreceptors detect?
Changes in arterial PO2 and [H+]
