Breathing Faster Flashcards
Breathing is controlled by a breathing centre in the…
Medulla of the brain
Normal breathing is mainly involuntary, meaning it is a…
Reflex action
2 parts to the breathing centre:
Inspiratory and expiratory
Inspiratory stimulates breathing in by…
Sending impulses along the phrenic nerve to the diaphragm
and along the intercostal nerves to the intercostal muscles
When impulses are sent along the phrenic nerve and intercostal nerves the …
Diaphragm and intercostal muscles contract causing inspiration
Expiratory: when lungs inflate the alveoli fill with air, stretch receptors in the wall of the…
Alveoli and bronchioles are stimulated as the alveoli fill
Stretch receptors send impulses to the…
Expiratory centre of the medulla causing inspiration to be inhibited and expiration to be stimulated
No more impulses pass along the phrenic nerve and the intercostal nerves so the…
Diaphragm and intercostal muscles relax (expiration)
No stretch receptors stimulated = expiratory centre no long stimulated so inspiratory centre causes…
Inspiration again - cycle continues
When exercising the cells respire more, producing more…
Carbon dioxide
Respiring cells also need more…
Oxygen (breathing rate increases wen exercising)
The main stimulus to increase breathing rate is…
Carbon dioxide concentration in blood
Carbon dioxide is slightly acidic and dissolves in blood plasma to form…
Weak carbonic acid
Carbonic acid dissociates into:
Hydrogen ions and hydrogencarbonate ions
CO2 + H2O
H+ HCO3-
