Yes, alveoli are closely associated with endothelium; specifically, they are adjacent to capillary endothelium, which forms part of the air-blood barrier.
Alveoli and Endothelium: A Closer Look
The alveoli are tiny air sacs in the lungs where gas exchange occurs. The alveolar septum, or wall, is critical for this process. It consists of three primary components:
- Epithelium: This lines the alveolus or air space.
- Interstitium: This is the supporting tissue.
- Capillary Endothelium: This lines the capillaries that run alongside the alveoli.
The Air-Blood Barrier
The air-blood barrier is formed by the thin epithelial lining of the alveoli and the adjacent endothelium of the capillaries. This close proximity facilitates efficient gas exchange (oxygen and carbon dioxide) between the air in the alveoli and the blood in the capillaries. Essentially, the gas exchange occurs across the epithelium and endothelium.
