Luftvägsväggen

Luftvägsväggen refers to the structural components that form the walls of the airways in the respiratory system. This encompasses a complex arrangement of tissues designed to facilitate airflow, protect the lungs, and participate in gas exchange. The layers of the luftvägsväggen vary depending on the size and location of the airway, from the larger trachea and bronchi to the smaller bronchioles.

In larger airways like the trachea, the luftvägsväggen is characterized by a C-shaped cartilaginous framework that provides structural support, preventing collapse during inhalation and exhalation. This cartilage is embedded within connective tissue. Beneath the cartilage, a submucosa contains glands that produce mucus, which traps inhaled particles and pathogens. The innermost layer is the mucosa, lined with pseudostratified ciliated columnar epithelium. The cilia beat rhythmically to move the mucus and trapped debris upwards towards the pharynx for elimination.

As airways branch into smaller bronchi and then bronchioles, the proportion of cartilage decreases, eventually disappearing entirely in the smallest bronchioles. The smooth muscle layer becomes more prominent in these smaller airways, allowing for regulation of airflow through bronchoconstriction and bronchodilation. The epithelium also becomes simpler, transitioning to cuboidal cells. The terminal bronchioles lead into the alveoli, where the luftvägsväggen becomes extremely thin, consisting primarily of a single layer of squamous epithelial cells and the basement membrane, facilitating efficient gas exchange with the pulmonary capillaries. This intricate structure ensures the continuous and efficient passage of air to and from the lungs.