Mucus
Mucus is a thick, slimy substance that is produced by the body to help lubricate and protect certain organs and tissues. It is made up of water, proteins, and other compounds, and is produced by specialized cells in the body called goblet cells.
Mucus is found in various parts of the body, including the respiratory tract, digestive system, and reproductive system. In the respiratory tract, mucus helps to trap dust, bacteria, and other particles, preventing them from entering the lungs. In the digestive system, mucus helps to protect the lining of the stomach and intestines from the acid and digestive enzymes that are present. In the reproductive system, mucus helps to lubricate the vagina and facilitate sperm transport.
Mucus can become thicker and more abundant in response to irritation or infection, leading to symptoms such as coughing, sneezing, and nasal congestion. When mucus becomes discolored, such as when it is yellow or green, it may be a sign of an infection. In some cases, excess mucus production can also be a symptom of certain medical conditions, such as allergies, asthma, or cystic fibrosis.