infections
Defenses Against Infection
Natural Barriers Against Infection
 Structure and Function of the Skin None Mucous membranes,such as the lining of the mouth, nose, and eyelids, are also effective barriers. Typically, mucous membranes are coated with secretions that fight microorganisms. For example, the mucous membranes of the eyes are bathed in tears, which contain an enzyme called lysozyme that attacks bacteria and helps protect the eyes from infection. Overview of the Respiratory System None Overview of the Digestive System None Overview of the Urinary Tract None Vagina None 