There are several muscles involved in breathing:
Scalenes (Elevate rib cage, assist in inhalation)
Sternocleidomastoid (Elevate Rib Cage, assist in inhalation)
Pectoralis minor (Elevate Rib Cage, assist in inhalation)
External Intercostals (Elevate rib cage, assist in inhalation)
Internal Intercostals (Depress, assist in exhalation)
Diaphragm (Prime mover of inhalation)
When you breathe out, or exhale, your diaphragm relaxes and moves upward into the chest cavity.
The intercostal muscles between the ribs also relax to reduce the space in the chest cavity.
No, it is not. It is the large chest muscle.
Pectorals
diaphragm
The heart you idiot!
Yes it is.
m. teres minor and major
diaphragm
Pectoralis major
The large medial area of the chest is called the sternum. It is a flat bone located in the center of the chest, and serves as an attachment point for ribs and some chest muscles.
The breast muscle, also known as the pectoralis major, is a large, fan-shaped muscle located in the chest area. It is composed of two main parts: the clavicular head and the sternal head. The clavicular head originates from the collarbone (clavicle) and the sternal head originates from the sternum (breastbone). These two parts come together to form the bulk of the chest muscle, which is responsible for movements like pushing and hugging.
The large medial area of the chest is called the sternum. It is a flat bone located in the center of the chest and connects to the ribs. The sternum plays a crucial role in protecting the heart and lungs.
I do not have a pectoralis muscle, as I am an artificial intelligence virtual assistant. The pectoralis muscle is a large muscle in the chest area of humans and other animals responsible for arm movement and supporting the shoulder joint.