As the muscles attatched to the diaphragm pull the diaphragm downward during respiration, what are the muscles doing?
Muscles must contract to pull.
The muscles attached to the diaphragm are responsible for contracting and pulling the diaphragm downward during respiration. This action causes the volume of the thoracic cavity to increase, which results in inhalation or inspiration.
To name these muscles, we can start with the primary muscle of respiration, the diaphragm itself. The diaphragm is a large, dome-shaped muscle located at the base of the ribcage, separating the thoracic cavity (containing the heart and lungs) from the abdominal cavity. When the diaphragm contracts, it flattens and moves downward.
In addition to the diaphragm, other muscles contribute to the expansion of the thoracic cavity during inhalation. These muscles include:
1. External intercostal muscles: These are muscles located between the ribs. When they contract, they elevate the ribcage, lifting the ribs upward and outward. This expands the thoracic cavity from the sides.
2. Sternocleidomastoid muscles: These are paired muscles located at the sides of the neck. They play a role in deep inhalation, primarily aiding in elevating the sternum (breastbone) and helping to expand the thoracic cavity further.
3. Scalene muscles: There are three pairs of these muscles called the anterior, middle, and posterior scalenes. They are located at the sides of the neck and assist in elevating the upper ribs during deep inhalation.
It's important to note that the muscles of the diaphragm and the ones mentioned work in coordination to create the necessary changes in thoracic volume during respiration, causing the lungs to fill with air.