GROSSLY AND MICROSCOPIC STUDY OF THE TRACHEA AND BRONCHIAL TREE IN THE LOCAL SHEEP ( OVIS ARIS).

Abstract

The trachea of the local sheep is a tubular structure that begins at the cricoid cartilage of the larynx and ends when it bifurcates to form the principle bronchi, composed of series of incomplete rings that were incomplete dorsally present between of them longitudinal folds. The study include twelve specimens divided into four groups grossly, histological study, cast and radiography. The anatomical study include the mean total tracheal length from the first ring to the bifurcation about (25.9 cm) , mean number of cartilaginous rings (48.6), mean number of folds (45), measured the length of trachea from the cricoids cartilage to the trachealis bronchus which enter to the cranial lobe of lung which branches from the trachea in last third before divided into two bronchi right and left each of one enter the lung for respiration also measure diameters of each tracheal ring which deference according the position of rings, which decrease of diameters when direction caudally to the root of lung the rings have different shape in the three parts of the trachea cervical, middle and thoracic the histological study showed the trachea lining pseudo stratified ciliated columnar epithelium with goblet cells, the wall of trachea consist of mucosa, submuosa, hyaline cartilage and adventitia and have large amount of tracheal gland,the trachealis muscle composed of elastic fibers interupted with smooth fibers.The cast of trachea showed the bronchial tree and radiography explain the trachea , bronchi and bronchioles.