Respiratory System Flashcards
Define tidal volume?
Volume of air inspired or expired per breath
What is the unit for tidal volume (TV) ?
L (litres)
What’s the resting value for tidal volume?
500ml / 0.5L
What’s tidal volume like during exercise?
1.75L - 3L
Define frequency?
The number of breaths per minute (breathing rate)
What is the resting volume for frequency?
12 -15 breaths per minute
What’s frequency like during exercise?
Increases to 40 - 60 breaths per minute
What is minute ventilation?
Volume of air inspired/expired per minute
What is the calculation for minute ventilation?
Tidal volume x Frequency = Minute Ventilation
TV x f = VE
What’s the resting value of minute ventilation?
6 - 7.5 L/min
What is minute ventilation like during exercise?
120 - 210 L/min
What type of process is inspiration at rest?
Active
What is meant by an active process?
Muscles are actively working/contracting
Describe what the mechanics of breathing during inspiration at rest?
- Diaphragm and external intercostals contract
- Diaphragm flattens and rib/sternum moves up an out
- Thoracic Cavity volume increases
- Air Pressure in lungs decrease below atmospheric air
- Air rushes into the lungs to equate the pressure
What type of process is expiration at rest?
Passive
What is meant by a passive process?
Muscles are relaxing/inactive
Describe the mechanics of breathing during expiration at rest?
- Diaphragm and external intercostals relax
- Diaphragm pushed upwards and rib/sternum moves in an down
- Thoracic Cavity volume decreases
- Air Pressure in lungs increases above atmospheric air
- Air rushes out of the lungs (forced out due to difference in pressure)
Describe the mechanics of breathing for INSPIRATION during EXERCISE?
Diaphragm and external intercostals contract
- Sternocleidomastoid, Scalenes and pectoralis minor contract
- Diaphragm flattens with more FORCE and rib/sternum moves up an out with INCREASED DISTANCE
- Thoracic Cavity volume increases FURTHER
- Air Pressure in lungs decrease FURTHER below atmospheric air
- MORE Air rushes into the lungs to equate the pressure
Describe the mechanics of breathing for EXPIRATION during EXERCISE?
Diaphragm and external intercostals relax
- Internal intercostals, Rectus Abdominis and obliques contract
- Diaphragm pushed up with more FORCE
- Rib/sternum pulled in and down
- Thoracic Cavity volume decreases to a LOWER LEVEL
- Air Pressure in lungs increases FURTHER above atmospheric air
- MORE Air Forced out of the lungs to equate the pressure
Which 5 muscles are involved in expiration during exercise?
Diaphragm and external intercostals (relax)
Obliques, Rectus Abdominis and Internal intercostals (contract)
Which 5 muscles are involved in inspiration during exercise?
Diaphragm and external intercostals (contract)
Sternocleidomastoid, scalenes and pectoralis minor (contract)
Explain the regulation (neural) of breathing during REST/RECOVERY?
- Baroreceptors detect an decrease in blood pressure
- Chemoreceptors detect a decrease in carbon dioxide and lactic acid but an increase in oxygen
- Proprioceptors detect a decline in movement
- The receptors send a signal to the RCC (respiratory control centre) in the medulla oblongata
- In the RCC the ICC (inspiratory control centre) sends a signal to the diaphragm (via the phrenic nerve) and to the external intercostals (via the intercostal nerve)
- In the RCC the ECC (Expiratory control centre) is inactive during rest because it’s a passive process.
Explain the regulation (neural) of breathing during EXERCISE?
- Baroreceptors detect an increase in blood pressure
- Chemoreceptors detect a increase in carbon dioxide and lactic acid but an decrease in oxygen
- Proprioceptors detect a increase in movement
- The receptors send a signal to the RCC (respiratory control centre) in the medulla oblongata
- In the RCC the ICC (inspiratory control centre) sends a signal to the diaphragm (via the phrenic nerve) and to the external intercostals (via the intercostal nerve). It also recruits additional muscles; Scalenes. sternocleidomastoid and pectoralis minor to contract causing increased stroke volume
- In the RCC the ECC (Expiratory control centre) becomes active during exercise sending a signal to the obliques, internal intercostals and rectus Abdominis to contract to increase frequency
Where does external respiration take place?
Alveolar Capillary membrane
- Between alveoli air and capillary blood