Chp 10-Breathing Physiology

Question 1

Inspiration

Answer 1

1. R1-7 elevate & rotate
   - gentle = external intercostal mm; forced = pectoralis minor &
   scalenes
   - increases ant-post volume, reduces pressure
2. Diaphragm contracts, flattens & pushes down into the abdominal
   cavity
   
   • presses abdominal contents down & raises vertical volume

Question 2

Expiration

Answer 2

1. Quiet
   - R1-7 depresses -> mm. are relaxed, uses gravity
   - decreases volume & increases intrathoracic pressure
2. Forced
   - rib depression -> internal intercostal mm.
   - diaphragm elevates & increases intrathoracic pressure as it
   relaxes and/or the abdominal push against it, flattening it out.
   - abdominals: internal & external obliques, rectus abdominis

Question 3

Muscles involved in Inspiration and Expiration

Answer 3

intercostals, pectoralis minor, scalenes, diaphragm, plus serratus posterior, internal/external obliques, rectus abdominis