Pulmonary surfactant is a surface active material composed of lipids and proteins which is found in the fluid lining the alveoli.
Surfactant prevents alveolar collapse. In addition, it is involved in the protection of the lungs from injuries and infections caused by inhaled particles and micro-organisms.
I think that it protects them because they like swish them about and make them covered by a mucusy layer which then protects them further called bronchilus. this eventully stops any damage at all in the alveoli
The respiratory surface in humans is called the alveoli. These tiny air sacs in the lungs are where gas exchange occurs, with oxygen from the air we breathe passing into the bloodstream and carbon dioxide moving out.
lining of the tubes changes from ciliated columnar to simple squamous epithelium in the alveoli
The respiratory membrane consists of three main structures: the alveolar epithelium, the capillary endothelium, and the fused basement membranes of both. The alveolar epithelium is a thin layer of cells lining the alveoli, while the capillary endothelium forms the inner lining of the pulmonary capillaries. Together, these structures facilitate efficient gas exchange between the air in the alveoli and the blood in the capillaries.
Your stomach has a mucus lining that protects it from the acid. Cells located in your stomach produce this lining.
Usually there is a lining of mucous that protects the inner lining of the stomach from the gastric acid.
alveoli
Alveoli
Alveoli
The fatty molecule on the respiratory membrane is called a surfactant. Surfactant helps reduce the surface tension of the fluid lining the alveoli in the lungs, allowing for easier expansion and preventing the alveoli from collapsing during exhalation.
Mucus protects the stomach and intestinal linings.
At the top of the respiratory system, the nostrils (also called nares) act as the air intake, bringing air into the nose, where it's warmed and humidified. Tiny hairs called cilia protect the nasal passageways and other parts of the respiratory tract, filtering out dust and other particles that enter the nose through the breathed air. :D hope it helps