Fibromusculocartilaginous layer of trachea

The fibromusculocartilaginous layer of the trachea refers to the composite structural layer of the tracheal wall that includes hyaline cartilage, fibrous connective tissue, and smooth muscle fibers. Anatomically, the trachea is composed of C-shaped rings of hyaline cartilage that provide rigidity and maintain airway patency, with the open ends of the rings bridged posteriorly by the trachealis muscle (smooth muscle) and a fibroelastic membrane. The fibrous tissue is present both as a thin layer on the inner surface and a thicker layer on the outer surface of the cartilage, merging at the margins of the rings. This arrangement forms a continuous, supportive, and flexible framework that allows the trachea to resist collapse while permitting some degree of movement and compliance during respiration and swallowing.

The fibroelastic membrane, which is part of this layer, contains longitudinal elastic fibers and is closely associated with the trachealis muscle, contributing to the elasticity and dynamic properties of the tracheal wall.The combination of cartilage, fibrous tissue, and muscle is essential for the mechanical integrity and functional adaptability of the trachea.

Underlying structures in TA2:

• Tracheal cartilages

• Trachealis muscle

• Annular ligaments of trachea