The expansion of the larynx narrows to become the wind-pipe or trachea, which is the breathing tube of the neck: it is kept open by hoops of gristle and these can be felt in the neck below the ‘Adam’s apple, which indicates the position of the larynx. Entering the chest behind the breast-bone, the wind-pipe soon divides into two passages known as the right and left bronchi and leads to the right and left lungs respectively.
In the event of these bronchi becoming inflamed, in the condition known as ‘bronchitis’, we can now, having located them, realize why one of the symptoms will be rawness and discomfort behind the breast-bone and a feeling Of congestion in the chest. Irritation of the bronchi by inflammation brings about coughing which clears the air-tubes and protects the lungs.
When they reach the lung substance the two bronchi divide and sub-divide until the microscopic tubes, through which the interchange of stale and fresh air takes place in the act of breathing.