Practice!

Sample Problem

Label each of the following defenses with “1” for the first line of non-specific defense or “2” for the second line of non-specific defense:

Skin

Mucous membranes

Phagocytes

Interferon

Stomach acid

Solution

The answers are as follows: 1, 1, 2, 2, 1. The skin, mucous membranes, and stomach acid are all first – line defenses while the phagocytes and interferon are second – line defenses.