Week 3: Mechanics of Respiration Flashcards
In what type of breathing is inspiration active?
Both quiet and deep
In what type of breathing is expiration passive?
Quiet
In what type of breathing is Expiration active?
Deep
When do the diaphragm and intercostal muscles contract?
Inspiration
When do the diaphragm and intercostal muscles relax
Expiration
How does thoracic cavity expand?
The intercostals pull against the rib expanding the cavity into three planes
What are the three planes the thoracic cavity is expanded into?
Anterior, lateral, inferior
What are the accessory muscles in laboured breathing?
- sternocleidomastoid
- scalene
- pectorals
In laboured breathing what type of process is expiration?
Active
Pressure and Size of a container are what to each other, if the temperature stays the same?
Directly proportional
As thoracic cavity increases, what happens to the pressure?
Pressure decreases
As thoracic cavity decreases, what happens to pressure?
Pressure increases
How much % of inspired air contains oxygen?
21%
How much of expired air contains nitrogen and rare gases?
78%
Which gas will have the same %, inspired and expired?
Nitrogen
How is partial pressure calculated?
The total partial pressure of a mixture is calculated by the sum of all the pressures (P’s)
What is the pressure of a specific gas in a mixture of gases called?
Partial Pressure (P)
What Law is linked to pressure?
Daltons Law
What is atmospheric air pressure at sea level?
760mmHg
How is alveolar air different to atmospheric air?
It has more CO2 and less O2 and it has water saturation
Where do the alveoli allow efficient gas exchange between?
Between the air and the bloodstream
What is the partial pressure of O2 in alveolar air?
104mmHg
What is the partial pressure of CO2 in alveolar air?
40mmHg
By what process does the exchange of gases occour when a difference in partial pressure exists across a semi-permeable membrane?
Diffusion
