Which of the following is an example of a physical barrier, which is an innate defense mechanism?
A) secretions of sebaceous glands
B) fixed macrophages
C) perforins
D) cytokines
E) histamine and heparin

Question

Quizplus · Accepted Answer

Secretions of sebaceous glands form a physical barrier by producing sebum, which coats the skin and hair, making it difficult for pathogens to penetrate the surface. Fixed macrophages (B) are part of the body’s cellular defenses and are not a physical barrier. Perforins (C) are produced by natural killer cells and form pores in target cells, leading to their destruction, but are not a physical barrier. Cytokines (D) and histamine and heparin (E) are signaling molecules and chemical mediators of inflammation, respectively, and not physical barriers.

Which of the Following Is an Example of a Physical