How is it than made broader?
How is the change in the size of the thoracic cavity related to inspiration and expiration?
2007-02-26 13:39:46 · 2 answers · asked by To-the-Stars 4 in Science & Mathematics ➔ Biology
Longer - diaphram contracts and pulls downward.
Broader - muscles pull rib cage outward.
Bigger thoracic cavity - pulls air into the lungs. (inspiration)
Smaller thoracic cavity - pushes air out of the lungs. (expiration)
2007-02-26 13:44:12 · answer #1 · answered by ecolink 7 · 0⤊ 0⤋
there is a strip of flexible muscle in between the thoracic and abdominal cavity. That's called diaphragm. During respiration, the diaphragm moves down and increases the space of the thoracic cavity, which decreases the pressure in the lungs and so the air outside in inspired. (its not that breathing causes the changin of the diaphragm position.)
2007-02-26 14:17:17 · answer #2 · answered by guyfromthesky 2 · 0⤊ 0⤋