Respiratory system Flashcards
Define tidal volume
Volume of air inspired and expired per breath
What is the resting tidal volume for trained and untrained individuals?
Trained = 500ml
Untrained = 500ml
What is the maximal tidal volume for trained and untrained individuals?
Trained = 3-3.5l
Untrained = 2.5-3l
Define breathing rate
Number of breathes per minute
What is the resting breathing rate for trained and untrained individuals?
Trained = 11-12 breaths per minute
Untrained = 12-15 breaths per minute
What is the maximal breathing rate for trained and untrained individuals?
Trained = 50-60 breaths per minute
Untrained = 40-50 breaths per minute
Define minute ventilation
Volume of air inspired/expired per minute
Tidal volume X Breathing rate = Minute ventilation
What is the resting minute ventilation for trained and untrained individuals?
Trained = 5.5-6 l/min
Untrained = 6-7.5 l/min
What is the maximum minute ventilation for trained and untrained individuals?
Trained = 160-210 l/min
Untrained = 100-150 l/min
What happens during inspiration at rest?
Diaphragm (flattens) and external intercostals contract
Ribs move up and out
Volume increases
Pressure inside the lungs becomes lower than outside
Air rushes into the lungs to equal the pressure
What happens during inspiration during exercise?
Diaphragm (flattens), external intercostals, sternocleidomastoid and pectoralis minor contract
Ribs move up and out further
Volume increases greater
Pressure inside the lungs becomes lower than at rest than outside
More air rushes into the lungs to equal the pressure (increases the depth of breathing)
What happens during expiration at rest?
Diaphragm (curves) and external intercostals relax
Ribs move down and in
Volume decreases
Pressure inside the lungs becomes higher than outside
Air rushes out of the lungs to equal the pressure
What happens during expiration during exercise?
Diaphragm (curves) and external intercostals relax, and internal intercostals and rectus abdominus contract
Ribs move down and in further with force
Volume decreases more
Pressure inside the lungs becomes higher than at rest than outside
More air rushes out of the lungs to equal the pressure (increases the rate of breathing)
What regulates breathing rate and depth?
Respiratory regulation centre
What does the inspiratory centre do?
Stimulates inspiratory muscles to contract at rest/exercise
What does the expiratory centre do?
Stimulates expiratory muscles to contract during exercise
What happens to the RCC at rest?
Nerve impulses stimulate the inspiratory muscles
Intercostal nerve - external intercostals
Phrenic nerve - diaphragm
What control mechanisms tell the RRC what to do during exercise?
Chemoreceptors: decrease oxygen and increase carbon dioxide and blood acidity
Thermoreceptors: increase in blood temp
Proprioceptors: detect motor activity
Baroreceptors: detect pressure changes
What happens during inspiration (inspiratory centre)?
Chemo, proprio and thermo receptors send info to the RRC.
IC will increase the stimulation of diaphragm and intercostals
IC also recruits sternocleidomastoid and pectoralis minor to contract (increase depth of inspiration)
What happens during expiration (expiratory centre)?
Baroreceptors sends info the the EC.
Stimulates internal intercostals and rectus abdominus
Increase rate of breathing
Where do gases exchange during internal respiration?
Capillary blood - muscle cell = oxygen
Muscle cell - capillary blood = carbon dioxide
Where do gases exchange during external respiration?
Alveoli - capillary blood = oxygen
Capillary blood - alveoli = carbon dioxide
Describe external respiration at rest
Oxygen moves from a high pp in alveoli to a low pp in the capillary blood
Carbon dioxide moves from a high pp in capillary blood to a low pp in the alveoli
Describe internal respiration at rest
Oxygen moves from a high pp in the capillary blood to a low pp in muscle cell
Carbon dioxide from a high pp in the muscle cells to a low pp in capillary blood
What happens to both external and internal respiration during exercise?
Diffusion happens at a faster rate as the diffusion gradient steepens
How many oxygen molecules can 1 haemoglobin carry?
4
What happens to haemoglobin in lower partial pressures of oxygen?
Haemoglobin easily dissociates from oxygen
What is the Bohr Shift?
A move to the right of the oxyhaemoglobin due to a higher dissociation of oxygen from haemoglobin.
Why does the Bohr Shift occur?
Decrease in partial pressure of oxygen
Increase in partial pressure of carbon dioxide
Increase production of lactic acid and carbonic acids
Decrease in pH
Increase in blood and muscle temperature
What is the impact of performance of the Bohr shift?
At any given partial pressure of oxygen the percentage saturation of oxyhaemoglobin is lower.
The dissociation of oxygen to respiring tissues is higher.
This enhances volume of oxygen available for diffusion.
