Leslie Kaminoff’s YogaAnatomy.net has an interesting video extracted from his Online Course, which illustrates the functioning of the lungs and abdomenal cavity: Breathing: The Accordian & the Water Balloon. Leslie’s Yoga Anatomy is among the best yoga anatomy references available. More details about his online course are here. It’s expensive ($2,200), but it is a nine-month program that drills down into the finer details of the human body activated through yoga. This year’s course started on October 6, but Leslie keeps release 5 minute segments of class video that contain little nuggets of knowledge, like the accordian and balloon piece.