Respiratory: Questions - 15.2 Pulmonary Ventilation Flashcards
Inspiration + Expiration =
One cycle of pulmonary ventilation.
Pulmonary ventilation is commonly called:
Breathing
Airflow into and out of the lungs is due to the differences in _____________ and the pressure in the lungs (intrapulmonary pressure).
Atmospheric pressure
When atmospheric pressure is > intrapulmonary pressure :
Inspiration (inhalation occurs)
When atmospheric pressure is < intrapulmonary pressure:
Expiration (exhalation occurs)
A person breathes by changing the ________________pressure.
Intrapulmonary
Boyle’s Law states: If the volume of a closed container increases, the pressure in the container will _______________.
Decrease
Boyle’s Law states: If the volume of a closed container decreases, the pressure in the container will _______________.
Increase
So if the volume of the thoracic cavity (thus lungs) increases the intrapulmonary pressure _______________.
Decreases
If the volume of the thoracic cavity (thus lungs) decreases the intrapulmonary pressure _______________.
Increases
he prime mover (principal muscle) of inspiration is the ___________________.
Diaphragm muscle.
When the diaphragm relaxes, it pushes against the base of the ________________.
Lungs
When the diaphragm contracts, it flattens out to increase the _____________________size.
When the diaphragm contracts, it flattens out to increase the _____________________size. Thoracic cavity
When the diaphragm contracts, the thoracic size increases and thus the intrapulmonary pressure _________________.
Decreases
The external intercostals are synergist muscles that assist the diaphragm. They pull the _______ cage upward and the ________ upward. (Take a breath and feel what happens)
Rib, sternum
Forced inspiration is active. Name at least two muscles that help raise the rib cage to create a bigger lung volume.
- Sternocleidomastoid
* Serratus anterior
Normal quiet breathing (inspiration) is active. What two muscles are used?
- Diaphragm
* External intercostals
Normal expiration is passive. What muscles are used?
None. Passive means no energy is used. Normal expiration is due to the elastic recoil of the lungs.
What happens to the intrapulmonary pressure (pressure within the lungs) during quiet expiration?
It increases above atmospheric pressure thus forcing air out of the lungs.
Force expiration is active. What muscles are used to make the lung volume smaller (decrease in size)?
- Internal intercostals
* The abdominal muscles (external & internal obliques, and transverse abdominis).
Normal exhalation (expiration) is passive. What does that mean?
No energy is used; due to elastic recoil
What changes in the body to cause inhalation and exhalation?
Change in the lung size (thoracic cavity size)
The lung size is easy to change in the thoracic cavity since the ____________ is attached to the thoracic wall.
parietal pleura
When the pressure in the lungs (intrapulmonary) is higher than the atmospheric pressure what happens?
Inhalation (inspiration)
Muscles that raise the rib cage and sternum can increase the thoracic cavity size during forced inspiration. Name some of these muscles.
- Pectoralis minor
- Sternocleidomastoid
- Serratus anterior
Name some muscles that cause forced expiration.
- Internal intercostals
* Abdominal muscles
