Definition of air sac in English:

air sac

noun

  • 1A lung compartment containing air; an alveolus.

    • ‘There are about 15 million alveolar ducts, and each gives rise to about 20 alveolar air sacs.’
    • ‘The gas is capable of rupturing the air sacs in the lungs and causing immediate death.’
    • ‘Although the air sacs are connected to the lungs, they do not take part directly in gas exchange.’
    • ‘Once inhaled, the bacteria travel to the lungs and attach to air sacs, known as alveoli, where they multiply.’
    • ‘Inside your lungs, the bronchi subdivide nearly 20 times into a million smaller airways, which finally end in clusters of tiny air sacs called alveoli.’
    • ‘When lungs are damaged by tobacco the crimping elastic cells surrounding each air sac are broken and lungs become over inflated.’
    • ‘He saw a heart larger than a human's, an array of air sacs connected to the comparatively small lungs.’
    • ‘‘Pulmonary’ refers to the lungs' tiny air sacs, where oxygen and carbon dioxide are exchanged.’
    • ‘It affects the air sacs in your lungs, making the process of getting oxygen out of your lungs and into your bloodstream more difficult.’
    • ‘Your lungs contain millions of small, elastic air sacs called alveoli.’
    • ‘For example, the tiny air sacs in lungs expand more than seven times when you inhale.’
    • ‘Abnormal breathing sounds, sometimes indicating fluid in the air sacs of the lungs.’
    • ‘Holes in the lungs occur as the alveoli air sacs break down.’
    • ‘Scientists also suspect that air pollutants might dampen the growth of alveoli, tiny air sacs in the lungs.’
    • ‘This prohibits us from observing and analyzing the dynamic changes of the entire air sac.’
    • ‘For instance, we also have many little air sacs in each lung and can survive if only some of them get damaged.’
    • ‘When the organism is inhaled, it lodges in the alveoli of the lungs, the little air sacs that exchange oxygen for carbon dioxide within the blood.’
    • ‘The respiratory tract is the passageway for air between the outer atmosphere and the tiny air sacs of the lungs (alveoli).’
    • ‘Each air sac is surrounded by elastic fibers that help the lung recoil after inspiratory stretching.’
    • ‘Scarring of the connective tissue, which supports the air sacs of the lungs (pulmonary fibrosis).’
    1. 1.1 An extension of a bird's lung cavity into a bone or other part of the body.
      • ‘The primary function of the avian pulmonary air sac system is lung ventilation.’
      • ‘The clear tones of birdsong emerge from internal air sacs that can inflate and deflate, much like a bagpipe's bladder.’
      • ‘In extant birds, the cervical and anterior thoracic vertebrae are pneumatized first, by diverticula of the cervical air sacs.’
      • ‘It is likely that the air sac systems of ornithodirans evolved primarily for lung ventilation, and this adaptation may have been one of the keys to the success of the group.’
      • ‘Nearly a century ago, scientists noticed that some dinosaur bones were ‘pneumatized,’ or possessed holes like those that house avian air sacs.’
      • ‘This indicates the presence of both a cervical and abdominal air sac, i.e. at least two of the five sacs present in modern birds.’
      • ‘The air is expelled by the front air sacs as the bird breathes out.’
      • ‘While doing this, they inflate and deflate the air sacs in their breasts, creating a booming sound.’
      • ‘The two researchers examined the air sac systems of some 200 modern birds and identified specific patterns showing which air sacs are found in which bones.’
      • ‘The system of air sacs in the avian respiratory tract allows one-way flow through an essentially rigid lung that is much more efficient than the balloonlike mechanism seen in all other air-breathing vertebrates.’
      • ‘All birds have an extensive air sac system in the thorax and abdomen.’
      • ‘During the breeding season, groups of males do their courtship display together, puffing out air sacs in their chest and spreading their tails.’
      • ‘If they did have air sacs as birds do, there is no way of knowing whether they also had a flow-through lung like birds.’
      • ‘Modern birds have a series of balloon-like air sacs in their bodies that reduce their weight and aid respiration.’
      • ‘Citing King as their source, Britt et al. stated that, ‘in turkeys the cervical air sac extends all the way to the free coccygeal vertebrae.’’
      • ‘Although avian lungs and air sacs are made of soft tissues, they have important connections with the skeleton.’
      • ‘Bird bones are hollow and filled with extensions of the body's air sacs, which are extensions of the lungs that allow for increased respiratory efficiency.’
      • ‘The lung / air sac system of birds profoundly affects their physiology.’
      • ‘This is probably because the air sacs of birds lie between the skeletal muscles and the viscera and can therefore cool the body core directly, whereas mammals must rely on evaporation from more peripheral sites.’
      • ‘Instead, birds have flexible air sacs (usually nine in number) that act as bellows to move air through the lungs.’