Inspiration „³ quiet, forced or deeper inspiration
¡EExpiration „³ quiet, forced or deeper expiration
Quiet inspiration
1.Contraction of intercostal m. „³elevate 2th -7th rotate costal arches „³ increase transverse diameter of chest
2.Contraction of intercostal m. „³ elevate sternal end of arch „³ increase anteroposterior diameter of chest
3.Contraction of diaphragm „³ decrease dome „³ increase vertical diameter of chest
Forces or Deeper insipration
1.Scalenus m. „³ elevate 1st & 2nd costal arch
2.Sternal head of sternomastoid„³ elevate manubrium
3.serratus poaterior superior and quadratus lumborum„³ steady lower ribs
Quiet expiration
1.Transverse abdominis, costal cartilage and elastic recoil of lumg
Deep or forced expiration
1. Oblique and transverse abdominal m., iliocostalis and latissimus dorsi