Examples of muscle diseases include muscular dystrophy. Nervous system diseases, such as paralysis, can lead to shortness of breath. Heart Diseases Many conditions that affect the heart and its capacity to move blood through the lungs can lead to shortness of breath. These conditions include valve diseases of the heart and others. Lung Tissue Diseases
Sternum, also called breastbone, in the anatomy of tetrapods (four-limbed vertebrates), elongated bone in the centre of the chest that articulates with and provides support for the clavicles (collarbones) of the shoulder girdle and for the ribs. Its origin in evolution is unclear.
In pectus excavatum, the sternum and costal cartilages are deformed, resulting in a horizontal narrowing of the chest, primarily on the posterior side. The sternum, or chest bone, is a long flat bone located in the center of the thorax, and the costal cartilages are the cartilages that connect the chest bone with the ends of the ribs. In appearance, the middle of the chest appear to be flat or concave, rather than slightly convex. Brachycephalic (short-nose) breed dogs are predisposed to this condition and in most cases are born with (congenital) this disability.