Physical lines of defense in the human body primarily include the following:
- Skin - Acts as a barrier to prevent pathogens from entering the body.
- Cilia - Tiny hair-like structures in the respiratory tract that help to trap and move particles and pathogens out of the airways.
- Mucous membranes - These line various body cavities and secrete mucus, which traps pathogens and foreign particles.
Additionally, while hair, nails, and teeth somewhat contribute to physical protection, they are not typically classified as primary lines of defense in the same way as skin, cilia, and mucous membranes. Hair can provide some barrier protection, while nails can protect the tips of fingers and toes. Teeth help in the mechanical breakdown of food but are not direct lines of defense against pathogens.
In summary, the most recognized physical lines of defense are the skin, cilia, and mucous membranes.
48 answers