f, TV, VE and its response to exercise Flashcards
What is the symbol for breathing rate?
f
What is the average resting breathing rate?
12-15 breaths
Definition of breathing rate
The number of inspirations or expirations (breaths) per minute
What is the symbol to represent tidal volume?
TV
What is the average resting tidal volume?
500ml
Definition of tidal volume
The volume of air inspired or expired per breath
What is the piece of equipment used to measure lung volumes?
Spirometer
What is the symbol used for minute ventilation?
VE
What is the equation to calculate minute ventilation?
VE = TV x f
Definition of minute ventilation?
The volume of air inspired or expired per minute
What is the average resting minute ventilation?
6-7.5 l/min
Why may an aerobic athletes VE be lower?
They have more efficient gaseous exchange and transport, they can meet the demands for oxygen more efficiently at rest
What is the comparison of values of f, TV and VE for an untrained and trained athlete at rest
What is breathing rate response to exercise?
-Increases in proportion to exercise intensity
-Increases to about 40-50 breaths per minute for untrained, 50-60 per minute for training
-Can plateau once demand is met in sub-maximal work
What is TV response to exercise?
-Increases in line with exercise intensity (up to 3 litres)
-Plateaus at sub-maximal intensity as demand is met
What is the values of TV at maximal intensity exercise for a trained and untrained performer?
Untrained - 2.5-3l
Trained - 3-3.5l
What is minute ventilation response to exercise?
-Increases in line with exercise intensity
-During sustained sub-maximal work VE can plateau, this represent oxygen demand and waste removal being met
-TV will reach its capacity but breathing frequency will continue to increase
What is the values of VE at maximal intensity exercise for a trained and untrained performer?
Untrained - 100-150 l/min
Trained - 160-210 l/min
What is the values of f at maximal intensity exercise for a trained and untrained performer?
Untrained - 40-50
Trained - 50-60
Explain according to the graph the response of VE to light exercise intensity?
- an anticipatory rise in VE prior to exercise due to release of hormone adrenaline
- a rapid increase in VE at the start of exercise due to increased breathing frequency and tidal volume to increase oxygen delivery and waste removal in line with exercise intensity
- A steady state VE throughout the sustained intensity exercise as oxygen supply meets demand
- An initial rapid and then more gradual decrease in VE to resting levels as recovery is entered and oxygen demand dramatically reduces
What is the different in VE for light and maximal intensity exercise?
-During maximal intensity, VE does not plateau as exercise intensity continues to increase, growing demand for oxygen and waste removal which VE must meet
-There will be a rapid decrease followed by a more gradual decrease in heavy-intensity exercise
What are the mechanics of inspiration at rest?
-Active process
-External intercostals muscles contract lifting the ribs up and out (internal intercostals relax)
-Diaphragm contracts and flattens
-Volume inside the thoracic cavity increases
-This lowers the pressure below atmospheric air pressure and forces air into lungs
-As gases move form a high pressure to low pressure
What are the mechanics of expiration at rest?
-Passive process
-External intercostals muscles relax, ribcage and sternum move in and down
-Diaphragm relaxes, returns to dome shape
-Decreased size of thoracic cavity
-Pressure increases above atmospheric air, so air is forced out of lungs
What are the mechanics of inspiration during exercise?
-Active process
-More muscles are recruited to increase breathing rate, more forceful contractions
-Sternocleidomastoid recruited, contracts to lift the sternum
-Pectorialis major recruited, contracts to life ribs more
-External intercostal muscles contract with more forceful contractions, whole internal intercostals relax, ribs move up and out more
-Volume of thoracic cavity increases more, pressure decreases more, larger concentration gradient, air enters lungs quicker
What are the mechanics of expiration during exercise?
-Active process
-Change from passive to active process due to increase depth and frequency of breathing during exercise
-External intercostal muscles relax
-Internal intercostals contract, pulls ribs down and in
-Diaphragm relaxes
-Rectus abdominus contracts, push diaphragm up with more forces
-Volume of thoracic cavity decreases more, increase in pressure above atmospheric pressure, larger concentration gradient, air forced out of lungs quicker
