Lung Volumes and Lung Volumes and CapacitiesCapacities

Learning ObjectivesLearning Objectives

Be familiar with the concepts of, and be able to measure Be familiar with the concepts of, and be able to measure lung volumes and capacities.lung volumes and capacities.

Understand the concepts of minute ventilation, tidal volume Understand the concepts of minute ventilation, tidal volume and ventilation rates during quiet breathing and during and ventilation rates during quiet breathing and during exercise.exercise.

Account for the differences in lung volumes and capacities Account for the differences in lung volumes and capacities between untrained and trained sportspersons.between untrained and trained sportspersons.

Lung VolumesLung Volumes

During normal quiet breathing, we inspire approximately 500ml of During normal quiet breathing, we inspire approximately 500ml of air. The same amount is exhaled during the process of expiration.air. The same amount is exhaled during the process of expiration.

The volume of air inspired and expired is known as The volume of air inspired and expired is known as TIDAL TIDAL VOLUMEVOLUME. .

Of this 500ml, only about 350ml makes its way into the alveoli. The Of this 500ml, only about 350ml makes its way into the alveoli. The other 150ml remains in the passageways of the nose, throat and other 150ml remains in the passageways of the nose, throat and trachea and is known as dead space.trachea and is known as dead space.

The volume of air which is inspired or expired in one minute is The volume of air which is inspired or expired in one minute is called called MINUTE VENTILATIONMINUTE VENTILATION and is calculated by multiplying tidal and is calculated by multiplying tidal volume by the number of breaths taken per minute.volume by the number of breaths taken per minute.

On average we breathe 12 to 15 times per minute, so our On average we breathe 12 to 15 times per minute, so our resting minute ventilation can be calculated as follows:resting minute ventilation can be calculated as follows:

VE = T.V x fVE = T.V x f

= 500ml x 15= 500ml x 15

= 7,500ml/min (7.51/min)= 7,500ml/min (7.51/min)

Lung volume Capacity Lung volume Capacity DefinitionDefinition Approximate normal values (ml)Approximate normal values (ml) Changes during exercise Changes during exercise

Tidal volume (TV)Tidal volume (TV) Volume inspired or expired per Volume inspired or expired per breathbreath

500500 Increases up to 3-4 litresIncreases up to 3-4 litres

Inspiratory reserve volume (IRV)Inspiratory reserve volume (IRV) Maximal volume inspired from Maximal volume inspired from end inspirationend inspiration

3,3003,300 DecreasesDecreases

Expiratory reserve volume Expiratory reserve volume (ERV)(ERV)

Maximal volume expired from Maximal volume expired from end expirationend expiration

1,000-1,2001,000-1,200 Slight decreaseSlight decrease

Residual volume (RV)Residual volume (RV) Volume remaining at end of Volume remaining at end of maximal expirationmaximal expiration

1,2001,200 Slight increaseSlight increase

Total Lung Capacity (TLC)Total Lung Capacity (TLC) Volume in lung at end of Volume in lung at end of maximal inspirationmaximal inspiration

Up to 8,000Up to 8,000 Slight decreaseSlight decrease

Vital Capacity (VC)Vital Capacity (VC) Maximal volume forcefully Maximal volume forcefully expired after maximal expired after maximal inspirationinspiration

5,5005,500 Slight decreaseSlight decrease

Inspiratory capacity (IC)Inspiratory capacity (IC) Maximal volume inspired from Maximal volume inspired from resting expiratory levelresting expiratory level

3,8003,800 IncreaseIncrease

Functional residual capacity Functional residual capacity (FRC)(FRC)

Volume in lungs at resting Volume in lungs at resting expiratory levelexpiratory level

2,4002,400 Slight increaseSlight increase

Dead spaceDead space Volume of air in the trachea etc Volume of air in the trachea etc that does not take part in that does not take part in gaseous exchangegaseous exchange

150150 NoneNone

Minute ventilationMinute ventilation Volume of air inspired/ expired Volume of air inspired/ expired per minute per minute

TE= TV x FTE= TV x F

7,5007,500 Large increase (200L/min) in Large increase (200L/min) in trained athletes trained athletes

Ventilation during exerciseVentilation during exercise When we exercise depth and rate of breathing When we exercise depth and rate of breathing

increases increases Tidal volume increases by using Inspiratory reserve Tidal volume increases by using Inspiratory reserve

volume and expiratory reserve volume.volume and expiratory reserve volume. These volumes These volumes decreasedecrease, while tidal volume , while tidal volume

increasesincreases- up to 6 x- up to 6 x Minute ventilation increasesMinute ventilation increases

Tidal Volume Tidal Volume (TV) x (TV) x frequency frequency (breaths/min)(breaths/min)

= minute = minute ventilationventilation

RestRest 500ml (0.5L) x 500ml (0.5L) x 1515

=7.5L/min=7.5L/min

Maximal workMaximal work 4,000 (4.0L) x 4,000 (4.0L) x 5050

= 200L/min= 200L/min

Ventilation during exerciseVentilation during exercise

Changes in ventilation occur before exercise Changes in ventilation occur before exercise beginsbegins

Anticipatory riseAnticipatory rise Result of hormones, stimulating the respiratory Result of hormones, stimulating the respiratory

centre- adrenalinecentre- adrenaline Once we start to exercise there is a rapid rise in Once we start to exercise there is a rapid rise in

ventilation due to nervous stimulationventilation due to nervous stimulation Sub max exercise-Sub max exercise- this slows down and steady this slows down and steady

state is reachedstate is reached Maximal exercise-Maximal exercise- ventilation increases until ventilation increases until

exercise is finished.exercise is finished.

Ventilation during exerciseVentilation during exercise

If intensity continues to rise to a point near If intensity continues to rise to a point near the athletes VO2 max (the athletes VO2 max (maximum amount of maximum amount of oxygen that can be taken in, transported oxygen that can be taken in, transported and utilised in one minuteand utilised in one minute) is reached, they ) is reached, they cant get enough oxygen to working muscles cant get enough oxygen to working muscles so will have to slow down or stop. so will have to slow down or stop.

Recovery…Recovery…

During recovery- ventilation drop During recovery- ventilation drop rapidly at first followed by a rapidly at first followed by a slower decreaseslower decrease

More intense the preceding More intense the preceding exercise- longer the recoveryexercise- longer the recovery

Removal of lactic acidRemoval of lactic acid

Guess Who??Guess Who?? Choose from one of the key words from today's lesson.Choose from one of the key words from today's lesson. Write it on the post it note and stick to your partners head.Write it on the post it note and stick to your partners head. They have to guess which key word they are by asking questionsThey have to guess which key word they are by asking questions You are only allowed to answer ‘Yes’ or ‘No’You are only allowed to answer ‘Yes’ or ‘No’

Tidal volume (TV)Tidal volume (TV) Inspiratory reserve volume (IRV)Inspiratory reserve volume (IRV) Expiratory reserve volume (ERV)Expiratory reserve volume (ERV)

Residual volume (RV)Residual volume (RV) Total Lung Capacity (TLC)Total Lung Capacity (TLC)

Vital Capacity (VC)Vital Capacity (VC) Inspiratory capacity (IC)Inspiratory capacity (IC)

Functional residual capacity (FRC)Functional residual capacity (FRC) Dead spaceDead space

Minute ventilationMinute ventilation Steady stateSteady state

VO2 maxVO2 max Anticipatory riseAnticipatory rise

AdrenalineAdrenaline SpirometerSpirometer