THE THORAX 



X02X 



The structure of the trachea will be described in connection with 

 the description of the windpipe in the neck. 



(Esophagus in the Thorax. — The oesophagus or gullet extends from 

 the pharjTix to the stomach. In the first part of its course it hes 

 in the neck, and this portion \sill be found described in connection 

 with that region. The thoracic part (see Fig. 422) extends from the 

 level of the upper border of the manubrium stemi to the level of 

 the body of the twelfth thoracic vertebra, where it passes through 



Epiglottis 



Great Coma of Hyoid Bone. 



Small Comu of Hyoid Bone. i . 



Body of Hyoid Bone... l 



Thyro-hyoid Membrane- — 

 Levator GIandube\ ___ 

 Thyroid<e Muscle/ ^ 

 Thyroid Cartilage 



Cricothyroid Membrane __ 



Pyramid- ■ 



Cricoid Cartilage "" 



Lateral Lobe of Thyroid Body- 



Isthmus- 



Tracbea— 



Right Bronchos 



Eparterial Bronchus. 



Hyparterial Bronchus. 



Left Bronchus 



Fig. 420. — ^The Hyoid Bone, Larynx. Trachea, Bronchi, akd 

 Thyroid Body (Anterior View). 



the oesophageal opening of the diaphragm, and terminates at the 

 cardiac orifice of the stomach. Its course is not quite vertical. 

 At its commencement the thoracic portion lies partially to the left 

 of the middle line, but as it descends it comes to occupy a median 

 position about the level of the fifth thoracic vertebra, and interiorly 

 it again inclines partially to the left. It occupies the superior 

 and posterior mediastinal spaces, and lies in front of the vertebral 

 column, accurately following the thoracic antero-posteiior curve. 



Relations — Anterior. — ^The trachea as low as the intervertebral 

 disc between the bodies of the fourth and fifth thoracic vertebrae ; 



