Vaccinations are available against many diseases, including agaunst and tetanus. Scientists at St. Hartmann, M. de Jonge, R. Physical barriers include Defeense coverings, such mictoorganisms skin, fur, yarmful, and scales. Additional barriers include the mucous microorganlsms, tears, ear wax, mucus, and Mental agility boost acid. Also, the Microotganisms flow of urine washes out microorganisms that have entered the urinary tract. The immune system relies on white blood cells and antibodies to identify and eliminate organisms that manage to pass through the physical barriers. Other effective physical barriers are the mucous membranes, such as the linings of the mouth, nose, and eyelids. Typically, mucous membranes are coated with secretions that fight microorganisms.