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.
Trace the pathway of air from the trachea to the respiratory zone. Trachea, to primary bronchi, to secondary bronchi, to tertiary bronchi, to smaller bronchi, to bronchioles, to terminal bronchioles, to respiratory zone. 7. Describe the difference between bronchi and bronchioles in terms of smooth muscle and cartilage. Bronchi have rings of cartilage that keep them open.