1 The bitch has been pushing hard for an hour with no results. 2  A puppy presents rear end first and the head is too large to clear the pelvic bones.  There has been more than two hours between births, but you can still feel puppies inside.
Bronchus / Bronchi / Bronchioles. The airways of the lungs. When a person takes in a breath of air, the air travels through the nose or mouth, into the larynx, then into the trachea, which is the main passageway into the lungs. The trachea divides into a right and left main bronchus.
The trachea â the tube connecting the throat to the bronchi. The bronchi â the trachea divides into two bronchi (tubes). One leads to the left lung, the other to the right lung. Inside the lungs each of the bronchi divides into smaller bronchi. The broncheoli - the bronchi branches off into smaller tubes called broncheoli which end in the pulmonary alveolus.