RS. Respiration Mechanics Flashcards
what is respiration in terms of breathing and tissue respiration?
breathing - gas exchange and the associated processes
tissue respiration - the aerobic metabolism in cells
what is ‘respiratory mechanics’?
- study of mechanical properties of the lung and chest well
- process by which air enters and leaves the lungs
what do the lungs do?
- bring air with oxygen into body
- expel waste gas produced from cells in the body
what causes death by lung disease?
inability to overcome changes in lung or chest mechanics
why do we breathe?
to maintain blood gas homeostasis
at what point do you become aware of your breathing?
severe exercise
at what point do you expel more co2 than intake of o2?
severe exercise
what is the function of the upper airway?
conduct air to lung:
humidify air - saturate with water
warm air - to body temp
filter air - clean up debris
what happens to inhaled particles?
stick to mucous that is moved towards the mouth by cilia
what type of epithelium lines upper airways to bronchioles?
pseudo-stratified ciliated columnar epithelium
what do goblet cells do?
produce mucous that catches debris and helps to clean airway
what happen in quiet breathing when inspiration is active?
- diaphragm contracts downwards pushing abdominal contents outwards
- external intercostals pull ribs outwards and upwards
what happens in quiet breathing when expiration is passive?
elastic recoil
what happens during strenuous breathing when inspiration is active?
greater contraction of the diaphragm and intercostals (10cm)
what happens in strenuous breathing when expiration is active?
internal intercostal muscles oppose external intercostals by pushing ribs down and inwards.
what happens to muscles during expiration in quiet breathing?
muscles are relaxed
elastic recoil
what type of diffusion takes place in inspiration and expiration in quiet breathing?
active
passive
what type of diffusion takes place in inspiration and expiration in strenuous breathing?
both active
how much does the diaphragm contract in quiet and strenuous breathing?
quiet = 1cm
strenuous = 10cm
what is intraplural pressure?
space between lung and chest wall
what is intrapulmonary pressure?
pressure within the lung
what is tidal pressure?
the amount of air taken in after every breath
- usually 500ml
what is the transpulmonary pressure ?
difference in pressure between the lung and pulmonary space
what is alveolar pressure?
pressure in lung alveoli
is the trans pulmonary pressure always positive or negative?
always negative
what triggers expiration?
?
describe the airflow at the beginning of inspiration?
no flow
- alveolar and barometric pressure = 0
what happens to the thoracic volume when the inspiratory muscles contract?
increases thoracic volume
what happens at the end of inspiration?
muscles stop contracting
thorax and alveoli stop expanding
no flow as alveolar/barometric pressures are equal
what happens to barometric and alveolar pressure during expiration?
alveolar pressure becomes more than barometric pressure
in healthy lungs, what intensity of breathing is most efficient?
low level of breathing
what is gas flow turbulent in high intensity breathing?
uses more muscles
what is functional residual capacity?
volume of air in lung at end of expiration during quiet breathing
why does the lung never collapse on itself?
- elastic recoil forces of lung, act to decrease lung volume
- outward recoil of chest wall acts to increase lung volume
what is the functional residual capacity at rest used for?
tell overall health of lungs
what is total lung capacity?
total volume the lungs can hold
what is reparatory mechanics?
study of mechanical properties if lung and chest wall
