Air sacs are thin walled non-muscular,non-vascular,non-elastic and bladder like membrane connected to the lungs Air sacs are only the inflated extensions of the mucous membrane of some blindly ending bronchioles Some of them extended to bones In pigeon there are nine major air sacs One of them is unpaired and others are paired Unpaired air sac is interclavicular Paired sac include cervical,anterior thoracic,posterior thoracic and abdominal air sacs Abdominal and posterior thoracic sacs get filled with fresh air during inspiration.so they are called inspiratory air sacs Others get filled with fresh air during expiration

1. AIR SAC OF BLUE ROCK PIGEON

2. AIR SACS

3. Features
• Air sacs are thin walled non-muscular,non-vascular,non-elastic and
bladder like membrane connected to the lungs
• Air sacs are only the inflated extensions of the mucous membrane
of some blindly ending bronchioles
• Some of them extended to bones
• In pigeon there are nine major air sacs
• One of them is unpaired and others are paired
• Unpaired air sac is interclavicular
• Paired sac include cervical,anterior thoracic,posterior thoracic and
abdominal air sacs
• Abdominal and posterior thoracic sacs get filled with fresh air
during inspiration.so they are called inspiratory air sacs
• Others get filled with fresh air during expiration

4. • Unpaired air sac
• Seen in the regoin of furcula
• Formed by the union of two sacs
• it has two lateral extensions known as accessory air sacs
• They are auxillary sac and extra clavicular sac
1) Interclavicular air sac
2) Cervical air sac
•These are pair of sac from each lung
•Located at the base of neck
3) Thoracic air sacs
•It include paired anterior thoracic and posterior thoracic sacs
•They extend from the outer side of lungs to the edge of
strenum
4) Abdominal air sacs
•Largest air sacs
•Lie among the coils of intestine
•Air sac may be connected to the adscent parts of lungs by
several air tubes called recurrent bronchi

5. Role of air sacs
• Reduce the specific gravity of the body and thereby decrease
body weight and increase lightness
• Act as bellows and bring about the efficiant of air in lungs
during respiration
• Serve as bellasts and euilibrium of body for balenced flight
• Function as accessory breathing organs
• Act as resonators
• Reduce mechanical friction during flight
• Promote internal prespiration and thereby help to regulate
body temperature

6. THANK YOU