The Respiratory System Flashcards
Passage of air
- Nose
- Pharynx
- Larynx
- Trachea
- Bronchi
- Bronchioles
- Alveoli
Ventilation Phases
- Inspiration
- Expiration
Muscles used during inspiration at rest
- Diaphragm
- External intercostals
Muscles used for expiration at rest
Passive (diaphragm and external intercostal muscles relax)
Muscles used for inspiration during exercise
- Diaphragm
- External intercostals
- Sternocleidomastoid
- Scalenes
- Pectoralis minor
Muscles used for expiration during exercise
- Internal intercostal muscles
- Abdominals
Inspiration
To breathe in
Expiration
To breathe out
Inspiration at rest
Diaphragm and external intercostals contract
Chest cavity/thorax volume increases
Pressure in chest is reduced
Air moves from higher pressure to lower pressure in the lungs
Expiration at rest
Passive
External intercostals and diaphragm relax
Volume of of lungs decreases
Pressure in lungs increases
Air moves from higher pressure in the lungs to lower pressure out of the body
Inspiration during exercise
Diaphragm, external intercostals, pectoralis minor, scalenes, sternocleidomastoid muscles contract
Increases the volume of lungs
Decreases the pressure in the lungs
Air moves down the pressure gradient into the lungs
Expiration during exercise
Assited by the contraction of internal intercostals and abdominal muscles
Volume of chest cavity decreases
Pressure in lungs increases
Air leaves from higher pressure in lungs to lower pressure in the atmosphere
What do alveoli do?
Take CO2 out of the blood stream to be breathed out
Diffuse O2 into the blood stream
Explain gaseous change in the alveoli
The CO2 diffuses out of the blood capillary into the alveoli from a high concentration to low concentration (down the concentration gradient)
The O2 diffuses out of the alveoli into the blood capillary from high concentration to low concentration (down the concentration gradient)
Features that assist gaseous exchange
- Large surface area of alveoli
- Moist thin walls (short diffusion pathway)
- Lots of capillaries
- Large blood supply
- movement of gas from high to low concentration
