In Depth: Muscles. The major muscle in the chest is the pectoralis major. This large fan-shaped muscle stretches from the armpit up to the collarbone and down across the lower chest region on both sides of the chest. The two sides connect at the sternum, or breastbone.
Listen for bowel sounds for atleast 1 min in each quadrant and you should hear anywhere from 5-30 bowel sounds in each quadrant. If you don't hear anything or (0-4 bowel sounds) in a quadrant after 1 minute listen for a full 5 min. 0 to 4 bowel sounds heard in 5 min are called hypoactive Bowel sounds, more than 30 bowel sounds in a minute are called hyperactive... Hope this helps you ;--) May 14, '09.
Absence of bowel sound - established only after 5 minutes of continuous listening. Caused by an immobile bowel of adynamic ileus (peritonitis, severe hypokalemia, complete obstruction, paralytic ileus, gangrene). A full bladder can obscure sounds.