Respiratory system Flashcards
What are the 2 principal areas of the respiratory system?
-The medullary respiratory centre in the medulla oblongata
-The pontine respiratory centre in the pons
What area sets the basic rhythm of respiration?
The inspiratory area in the medualla oblongata
What can respirations be modified by?
-cortical influences
-chemoreceptors
-limbic system stimulation
-proprioceptor stimulation
-temperature
-pain
-irritation of airways
-inflation reflex
Explain the process of normal quiet inhalation when the Dorsal respiratory group is active
-Diaphragm contracts and external intercostal muscles contract during their most active phase
-Ribcage moves upwards and outwards
-Pressure decreases inside the lungs to below atmospheric pressure, drawing air in from the environment
Explain the process of normal quiet exhalation when the Dorsal respiratory group is inactive
-Diaphragm relaxes and external intercostal muscles becomes less active and relax, followed by elastic recoil of lungs
-Ribcage is pulled downwards and inwards
-Pressure increases inside the lung to above atmospheric pressure, forcing air out into the environment
Explain the process of forceful inhalation
-Dorsal respiratory group (DRG) activates the ventral respiratory group (VRG)
-Diaphragm contracts and external intercostal muscles contract during their most active stage
-Accessory muscles of inhalation contract
=forceful inhalation
Explain the process of forceful exhalation
-Ventral respiratory group causes accessory muscles of exhalation to contract
=forceful exhalation
During exercise, what does both the respiratory and cardiovascular systems make adjustments to?
The intensity and duration of exercise
What is the abrupt increase in ventilation at the start of exercise due to?
Neural changes that send excitatory impulses to the inspiratory area in the medulla oblongata
What is the more gradual increase in ventilation during moderate exercise due to?
Chemical and physical changes in the bloodstream
