ANATOMY

Detailed explanation-1: -According to the ‘septation’ model, foregut division occurs when paired epithelio-mesenchymal ridges, arising from the lateral aspects of the foregut tube, fuse to form a septum. This separates the foregut lumen into dorsal (gastrointestinal) and ventral (respiratory) components (Qi and Beasley, 2000).

Detailed explanation-2: -As the foregut elongates, a wedge of mesoderm, the tracheoesophageal septum, separates the foregut (portion that will become the esophagus) from the future lungs.

Detailed explanation-3: -Tracheoesophageal folds develop on either side and join to form a tracheoesophageal septum that separates it from the rest of the foregut. This divides the foregut into the laryngotracheal tube (ventral) and the esophagus (dorsal).

Detailed explanation-4: -The tracheoesophageal septum is a structure which divides the the esophagus from the trachea. It divides the foregut tube into the laryngotracheal tube and esophagus. Developmental abnormalities can lead to a tracheoesophageal fistula.

Detailed explanation-5: -The trachea, commonly called the windpipe, is the main airway to the lungs. It divides into the right and left bronchi at the level of the fifth thoracic vertebra, channeling air to the right or left lung. The hyaline cartilage in the tracheal wall provides support and keeps the trachea from collapsing.