During inspiration, fresh air enters the respiratory system through the pared external nares (nostrils; shown here) and/or the oral cavity to the pharynx. Air then travels through the glottis into the trachea, through the bronchi and bronchioles to reach the alveoli.
The proximal attachments are the pubic crest and the pubic symphysis. It attaches distally at the costal cartilages of ribs 5-7 and the xiphoid process of the sternum.