Mechanisms of ventilation Flashcards
Under construction
Pulmonary ventilation
in the lungs movement of air in and out of lungs- breathing- supplying oxygen and eliminate carbondioxide.
Main muscles of inspiration
diaphragm and external intercostal muscles- contract voluntarily.
What shape is the diaphragm
dome
during respiration the external intercostal muscles extend…
downwards and forward.
What % of air movement is down to the diaphragm
70-75%
When the diaphragm contracts the muscle fibres
shorten and diaphragm is pulled down to flatten
When the diaphragm contracts a negative pressure is created in the thoracic cavity to air…
is pulled in
what nerve supplies the diaphragm
phrenic nerve
What is it called when the diaphragm controls the breathing when resting
diaphragmatic breathing
Where is the phrenic nerve
C345 - if you break neck and severe C345 phrenic nerve you can only breath through ventilator if you survive
If breathing is under high demand which muscle help
accessory muscles
What are the accessory muscle called
Sternocleidomastoid and Scalene.
Is inspiration active or passive
Active
Is expiration active or passive
Passive
Expiration occurs due to…
relaxation of the muscles and elastic recoil of the lungs
Cycle of breathin
Inspiration, expiration, pause.
How long is inspiration
2 secs
How long is expiration
3 secs
What is tidal volume
resting volume of air in lungs- 500ml
Deep breath out relies on…
Expiratory reserve volume- 1200ml
Air always left in lungs…
residual volume- 1200ml
Deep breath in/ over ventilate
Inspiratory reserve volume- 3100ml
Total lung capacity
5000ml
Vital lung capacity
4800ml
Functional residual capacity
2400ml
Inspiration capacity
3600ml
Elasticity
The ability for the lung to return to its normal self
Compliance
Effort required to inflate the alveoli
Airway resistance
broncho- constriction means more effort is required to inflate the lungs.
Daltons law
In a mixture of non-reacting gases, the total pressure exerted is equal to the sum of the partial pressures of the individual gases.
diffusion occurs to
a difference in the partial pressures of a gas on either side of a semi- permeable membrane
During diffusion of the air
The gas will diffuse from a high partial pressure to a low partial pressure.
What % of oxygen is carried by haemoglobin as oxyhaemoglobin?
98.5%
What % of oxygen is carried in plasma
1.5%
What % of carbondioxide is transported in the plasma
77%
What % of carbondioxide is carried as carbaminohaemoglobin
23%
Henrys law
The quantity of a gas that will dissolve in a liquid is proportional to…
WHats the respiratory centre in the brain
Respiratory (Medullary) Rhythmicity centre
