Ventilation Flashcards
What is inspiration?
When the pressure of air outside the body is greater than the pressure inside the lungs, causing air to move into the lungs.
What are the two parts of ventilation?
Inspiration and Exhalation.
What causes inspiration and exhalation?
Pressure differences between the lungs and environmental air.
What causes exhalation?
When the pressure of air outside the body is lesser than the pressure inside the lungs.
What are the three muscles used in ventilation?
- Diaphragm,
- Internal intercostals,
- External intercostals.
What causes inspiration?
When the pressure of air outside the body is greater than the pressure inside the lungs.
What is the diagphragm?
It separates the thorax from the abdomen, it contracts and relaxes to alter the volume of the thoracic cavity to change the pressure inside.
What is exhalation?
When the pressure of air outside the body is lesser than the pressure inside the lungs, causing air to move out of the lungs.
Is inspiration or expiration a passive process?
Inspiration.
Explain the process of inspiration:
- External intercostals contract,
- Ribs are drawn down and in,
- Diaphragm relaxes (arches up),
- Thorax volume decreases and lung pressure increases,
- Atmospheric pressure < lung pressure,
- Air rushes out of lungs.
What is the pressure difference between the atmospheric pressure and lung pressure during inspiration?
Atmospheric pressure < Lung pressure.
Inspiration involves the contraction of which muscles?
External intercostals and the diaphragm.
Is inspiration or expiration an active process?
Expiration.
What is the pressure difference between the atmospheric pressure and lung pressure during expiration?
Atmospheric pressure > Lung pressure.
What are the internal intercostals?
Contraction leads to expiration due to the decreased size of the thoracic cavity.
Contraction of the internal intercostals leads to what happening to the ribs?
The ribs are pulled upwards and outwards.
Contraction of the external intercostals leads to what happening to the ribs?
The ribs are drawn down and in.
Explain the process of expiration:
- Internal intercostals contract,
- Ribs are pulled upwards and outwards,
- Diaphragm contracts (flattens),
- Thorax volume increases and lung pressure decreases,
- Atmospheric pressure > lung pressure,
- Air rushes into lungs.
Expiration involves the contraction of which muscles?
Internal intercostals.
What are the external intercostals?
Contraction leads to inspiration due to the increased size of the thoracic cavity.
During which process does the diaphragm contract?
Inspiration.
How are lung volumes measured?
Spirometer.
What is the equation for pulmonary ventilation rate?
Pulmonary ventilation rate = Tidal volume x Breathing.
What is tidal volume?
Volume that enters and leaves with each breath, from a normal quiet inspiration to a normal quiet expiration.
