what is the accessory muscle used when people breathe during difficulty in breathing?

Answer 1

The diaphragm

Answer 2

It looks like they've done a great job listing the accessory muscles, so I'm not going to repeat what they said, but I just wanted to add my experience with this. My nine month old daughter has severe lung disease (Interstitial Lung Disease, Diffuse Alveolar Damage), and she uses intercostals, abdominals, and muscles in her neck to help her breathe. It is actually quite disturbing to watch (very violent looking), and when she was smaller, I would have to consciously ignore all the flailing going on in her chest just to be able to stand to hold her. As far as the diaphragm, she breathes so fast, it just kind of quivers a lot of the time. When I was a nursing student a few years back, I remember wondering about this, but now I know that if accessory muscles are being used, you won't miss it! What is amazing to me is how adaptive the human body is. When I imagine trying to breathe as fast as she does (average of 70 breaths per minute on a good day, in the 90's when she is feeling bad, and has been as high as 110-120 in the hospital), I get tired thinking about it, but my daughter does not even realize she is sick. She crawls all around the house, dragging the oxygen cord behind her huffing and puffing the entire way. Doesn't bother her a bit!

Answer 3

There are several accessory muscles used to assist when a person has difficulty breathing, some of which are used to assist in breathing in, and some are used to assist in exhaling.
There are muscles between the ribs in the rib cage called intercostal muscles which when contracted, help push the air out of the lungs and the muscles in the chest such as pectoralis, etc... are used to help breath air in.
The normal muscle used for inspiration is the diaphragm. When contracted, the bilateral dome shaped muscle flattens causing the chest wall to expand therefore creating a greater negative pressure allowing air outside with a high pressure to go into the area with an increased negative pressure. Exhalation is passive in that the diaphragm relaxes and goes back to it's domed shape causing a higher pressure within the chest cavity and the air moves outside to the area of lower pressure. If someone's diaphragm is impaired or if someone has lung disease requiring extra help to get air in or out, the accessory muscles are used. One pretty easily can see if someone is using accessory muscles. They will expand their chest by lifting up the chest wall with the muscles surrounding the upper chest. The spaces directly above the clavicle or breast bone will retract bilaterally, and you will also see nasal flaring, especially with infants. Hope this answers your question.

Answer 4

The accessory muscles of respiration are generally thought to include the: parasternal, scalene, sternocleidomastoid, trapezius, and pectoralis muscles. The abdominal muscles are also used at times to relieve pressure on the diaphragm, especially in the infant.

Answer 5

Intercostal muscles