ANATOMY

Detailed explanation-1: -The respiratory primordium maintains its communication with the pharynx through the laryngeal orifice (Fig. 13.2D). At about the time that the cartilages are formed, the laryngeal epithelium also proliferates rapidly, resulting in a temporary occlusion of the lumen.

Detailed explanation-2: -The primordium of the respiratory system develops from a diverticulum of the ventral wall of the primitive foregut with the formation of the tracheobronchial groove (primitive trachea) and two endodermal lung buds which invade the mesoderm and join at the midline to form the primordial lung.

Detailed explanation-3: -The trachea is the long tube that connects your larynx (voice box) to your bronchi. Your bronchi send air to your lungs. Your trachea is a key part of your respiratory system. The trachea is made of rings of cartilage.

Detailed explanation-4: -When you inhale through your nose or mouth, air travels down your pharynx (back of your throat), passes through your larynx (voice box) and into your trachea (windpipe). Your trachea is divided into two air passages called bronchial tubes. One bronchial tube leads to your left lung, the other to your right lung.

Detailed explanation-5: -EMBRYOLOGY AND CLASSIFICATION At the end of the third week of gestation, the laryngotracheal groove or diverticulum can be seen in the caudal end of the embryonic foregut. This groove arises as a ventral enlargement of the foregut and then grows caudad to form the primordium of the trachea and lung bud.