The trachea (also known as the windpipe) is a short, flexible air tube which extends from the larynx down to the middle of the thorax, where it divides into two main bronchi. It belongs to the respiratory system and provides air passage from the larynx and pharynx to the lungs.

The trachea is composed of fifteen to twenty C-shaped hyaline tracheal cartilages. The posterior part of each ring is made of smooth muscle fibers and connective tissue, forming a fibromuscular membrane known as the trachealis muscle.

The trachea extends downward from the larynx at the level of sixth cervical vertebra (C6). Then it travels behind the sternum and ends at a cartilaginous ridge called the carina of the trachea. It projects at the level of the fifth thoracic vertebra (T5) in the middle of the thorax. At this point, the trachea bifurcates and divides into the right and left main bronchi.

In adults, the diameter of the trachea is about 0.6 - 1 inches (1.5 - 2.5 cm), and it is around 4 - 5 inches (10 - 13 cm) long. Its size differs in men and women, as the trachea in males is typically wider and longer.

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Trachea