Because we expose our feet to potential injury in our daily lives by walking, we have all experienced pains in the feet at one time or another. There are many common causes of foot pains, such as blisters and corns. There are also less common causes of foot pain, such as sciatica and osteomyelitis.
The trachea, or windpipe (figs. 21-1 and 21-2), which has cervical and thoracic parts, extends from the inferior end of the larynx (C6 vertebra) to its point of bifurcation (between T5 and 7 vertebral level). It is about 9 to 15 cm in length. The trachea descends anterior to the esophagus, enters the superior mediastinum, and divides into right and left main bronchi. The trachea is a median structure but, near its lower end, deviates slightly to the right, resulting in the left main bronchus crossing anterior to the esophagus. Owing to the translucency of the air within it, the trachea is usually visible above the arch of the aorta in radiographs.
Just before the esophagus gets to the stomach, it travels through your diaphragm. The diaphragm is a broad muscle that separates your stomach from your chest cavity. The opening in the diaphragm where the esophagus travels through, is called the hiatus.. You'll hear more about the hiatus, and how it can be associated with GERD, a little later. The esophagus then joins the stomach at the lower esophageal sphincter, also called the LES..