Editing Common ostrich (section)

====Anatomy====
[[File:Ostrich Respiratory Anatomy.svg|thumb|Diagrammatic location of the air sacs]]
 
Morphology of the common ostrich [[lung]] indicates that the structure conforms to that of the other [[bird anatomy|avian species]], but still retains parts of its primitive [[ratite]] structure.<ref name=Makanya /> The opening to the respiratory pathway begins with the [[larynx|laryngeal]] cavity lying posterior to the [[posterior nasal apertures|choanae]] within the [[Mouth|buccal cavity]].<ref name=Deeming /> The tip of the tongue then lies [[anatomical terms of location|anterior]] to the choanae, excluding the nasal respiratory pathway from the buccal cavity.<ref name=Deeming /> The trachea lies [[Anatomical terms of location|ventrally]] to the cervical vertebrae extending from the [[larynx]] to the [[Syrinx (bird anatomy)|syrinx]], where the trachea enters the [[thorax]], dividing into two primary [[bronchus|bronchi]], one to each lung, in which they continue directly through to become mesobronchi.<ref name=Deeming /> Ten different air sacs attach to the lungs to form areas for respiration.<ref name=Deeming /> The most [[Anatomical terms of location|posterior]] [[air sacs]] (abdominal and post-thoracic) differ in that the right abdominal air sac is relatively small, lying to the right of the [[mesentery]], and [[Anatomical terms of location|dorsally]] to the liver.<ref name=Deeming /> While the left abdominal air sac is large and lies to the left of the mesentery.<ref name=Deeming /> The connection from the main mesobronchi to the more [[Anatomical terms of location|anterior]] air sacs including the [[clavicle|interclavicular]], lateral clavicular, and pre-thoracic sacs known as the ventrobronchi region. While the [[Anatomical terms of location|caudal]] end of the mesobronchus branches into several dorsobronchi. Together, the ventrobronchi and dorsobronchi are connected by intra-pulmonary airways, the [[bird anatomy|parabronchi]], which form an arcade structure within the lung called the paleopulmo. It is the only structure found in primitive birds such as ratites.<ref name=Deeming />
[[File:Struthio_syrinx.jpg|thumb|The syrinx has simple muscles. The only sounds that can be produced are roars and hisses.]]
The largest air sacs found within the respiratory system are those of the post-thoracic region, while the others decrease in size respectively, the interclavicular (unpaired), abdominal, pre-thoracic, and lateral clavicular sacs.<ref name=Schmidt-Nielsen /> The adult common ostrich lung lacks connective tissue known as interparabronchial septa, which render strength to the non-compliant avian lung in other bird species. Due to this the lack of connective tissue surrounding the parabronchi and adjacent parabronchial lumen, they exchange blood capillaries or [[blood vessel|avascular]] epithelial plates.<ref name=Makanya /> Like mammals, ostrich lungs contain an abundance of type II cells at gas exchange sites; an adaptation for preventing lung collapse during slight volume changes.<ref name=Makanya />