alveolærbasalmembranen

The alveolar basement membrane is a crucial component of the lung's gas exchange surface. It is a thin, non-cellular layer that lies beneath the alveolar epithelium, which forms the lining of the alveoli, the tiny air sacs in the lungs. This membrane plays a vital role in separating the air within the alveoli from the capillaries, the smallest blood vessels that surround them.

This delicate structure is composed of extracellular matrix proteins, primarily collagen and laminin. Its primary function is to act as a barrier, regulating the passage of substances between the air and blood. During respiration, oxygen from inhaled air diffuses across the alveolar epithelium, through the basement membrane, and into the blood within the capillaries. Simultaneously, carbon dioxide, a waste product of metabolism, diffuses in the opposite direction, from the blood into the alveoli to be exhaled.

The integrity and thinness of the alveolar basement membrane are essential for efficient gas exchange. Diseases that thicken or damage this membrane, such as pulmonary fibrosis, can significantly impair the lungs' ability to transfer oxygen and carbon dioxide, leading to respiratory distress. The basement membrane also contributes to the structural support of the alveoli, helping to maintain their shape and prevent collapse. Its composition and organization are finely tuned to facilitate the critical process of respiration.