What is mucus made of?

Mucus is a sticky substance inside the body and nasal cavities that consists of antibodies, enzymes, protein and a variety of cells, according to WebMD. Mucus can be a green, yellow or clear gooey substance.

Mucus-producing tissue lines the gastrointestinal tract, mouth, nose, throat, lungs and sinuses, forming a protective blanket that prevents needed tissues in the body from drying out, explains WebMD. The antibodies within mucus recognize viruses and bacteria, and the enzymes kill off infectious invaders. The body produces mucus on a regular basis, but more of the sticky substance develops when individuals are suffering from allergies or an infection.