Mechanical barrier

Mechanical barriers are physical structures, such as skin and mucous membranes, that constitute the body’s first line of defense by physically blocking the entry of pathogens into tissues[2][3][7]. These barriers include the tough outer layer of the skin, mucous membranes lining body openings, nasal hairs, and actions like sneezing or coughing that remove trapped pathogens[2][3][4]. Mechanical barriers are not single molecules or proteins, nor are they conventional drug targets, but rather anatomical features critical for innate immunity[2][7]. Mechanical barrier is therefore not a valid molecular or receptor target; it is a category of anatomical defense mechanisms in organisms rather than a discrete therapeutic target.

Other names

Physical barrierFirst line of defense