There are three principal layers; 1  External intercostal muscles aid in quiet and forced inhalation. They originate on ribs 1-11 and have their insertion on ribs 2-12. 2  Internal intercostal muscles aid in forced expiration (quiet expiration is a passive process).
Costs. A professional concrete contractor will typically charge $2-$4 per square foot for a simple stain application, including the sealer. A stain application with patterning and sawed lines will typically cost between $4 and $10 per square foot.
Decorative options such as stamping (see stamped concrete cost), staining (see stained concrete cost), and special finishes will add significantly to the cost of the project. For plain concrete, you can expect your price to fall somewhere between $3.25 and $5.25 square foot depending on the project size and complexity.Tip. Get a quote from a professional, they can often do the project at or below your cost due to economies of scale and access to the proper equipment.ecorative options such as stamping (see stamped concrete cost), staining (see stained concrete cost), and special finishes will add significantly to the cost of the project. For plain concrete, you can expect your price to fall somewhere between $3.25 and $5.25 square foot depending on the project size and complexity.