Components of the First Line of Defense Include All the Following

Question

Components of the first line of defense include all the following except ________.
A)the tough cell sheet of the upper epidermis of the skin
B)nasal hairs
C)flushing action of tears and blinking
D)flushing action of urine
E)phagocytic white blood cells

Accepted Answer

Phagocytic white blood cells are not a component of the first line of defense. They are part of the second line of defense, which involves innate immune responses such as inflammation and phagocytosis. The first line of defense consists of physical and chemical barriers such as the skin, mucous membranes, nasal hairs, tears, and urine.