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.
Confidence votes 261K. Trachea contain cartilage rings, and is the long tube that goes to the lungs. The bronchi contain cartilage plates and are the branching tubes that go to the lungs.Structure of the trachea  The trachea is lined by cartilage and divided into two branches. These two branches are called the bronchi.