Air sacs of fowl

AIR SACS OF FOWL

  • The air sacs are thin walled sacs lined with mucous membrane and covered by serous membrane
  • They all form a means of communication between a bronchus and the interior of some of the pneumatic bones
  • There are eleven sacs, cervical, clavicular, axillary, cranial thoracic, caudal thoracic and abdominal. All are paired except the clavicular, which is single
  • The thoracic air sac does not communicate with pneumatic bones
  • The primary function of the air sacs is to compensate for the small total capacity of the bird’s lung with the aid of respiratory muscles, they act as bellows to ventilate the lung in such a manner that a continuous stream of air passes through the air capillaries both during inspiration and expiration
  • This function carried out mainly by caudal thoracic and abdominal air sacs. All the air sacs together contribute to the reduction of the specific gravity of the avian body
  • It is playing vital role in the regulation of the body temperature
  • It also helps in even distribution of the body weight during the flight and in voice production
Last modified: Friday, 16 July 2010, 6:42 AM