Respiratory System. Air sac air-filled spaces in the body alveoli very small air sacs; where air breathed in goes. - ppt download
Air Sacs - an overview | ScienceDirect Topics
Anatomy of Your Child's Respiratory System | Saint Luke's Health System
Air Sac - an overview | ScienceDirect Topics
Secret Air Sacs Made This Dinosaur Extra Light - Scientific American Blog Network
The New York Times on Twitter: "Human lungs are made up of millions of microscopic, balloon-shaped air sacs called alveoli, the workhorse of the respiratory system, where the exchange of gases takes
How Your Lungs Work
Bronchioles and alveoli in the lungs - Mayo Clinic
Respiratory system - Wikipedia
Definition of alveoli - NCI Dictionary of Cancer Terms - National Cancer Institute
When Breathing Doesn't Come Naturally | El Camino Health
Bronchioles and alveoli - Mayo Clinic
What are the Effects of Dust on the Lungs? : OSH Answers
Emphysema | Beacon Health System
Air Sac Images, Stock Photos & Vectors | Shutterstock
Alveoli (air sacs) massively increase the surface area of the lungs for diffusion. | Body systems, Idiopathic pulmonary fibrosis, Respiratory system
Chickscope 1.5: Explore: Embryology: Day 15 - The Respiratory System: How Birds Breathe