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 bronchial tree is an essential part of the respiratory system. It consists of several interacting structures, such as the bronchi, bronchioles, and alveoli. These structures work together to provide a network system between the lungs and the trachea.Without this system, a person could not breathe properly.he primary bronchi also branch off, forming two smaller bronchial tubes known as the lobar bronchi, or secondary bronchi. There are three lobar bronchi on the right side and two on the left. The bronchiole treeâs parts continue reducing in size as these secondary bronchi become smaller tubes known as the bronchioles.