Mucosa, protective barrier and immune system
The mucous membrane, also called mucosa, refers to a protective layer that lines the walls of hollow organs, such as the lungs, stomach or intestines. It is also found in the conjunctiva, the nasal and oral cavities, or even in the genital organs.
The mucous membranes are designed to prevent pathogens (pathogens such as bacteria, viruses, fungal spores, etc.) from entering the body; they are natural protective barriers. Human mucous membranes are the first barrier to the outside world. Thus, they are the first line of defense against pathogens. In addition, a large part of the immune system is located in the mucosa. It is referred to as "mucosa-associated lymphoid tissue" (MALT). The MALT consists of different demarcated spaces (compartments). Each compartment has its own specific immune response. These include, for example, the tonsils in the pharynx, the appendix, the Peyersche's plaques in the small intestine, etc. Let's take a look at the nasal mucosa for example, it consists of the so-called respiratory mucosa and is the first protective barrier to the respiratory tract. Every day we breathe in and out about 20,000 times. In the process, irritating pollutants and numerous pathogens (bacteria, fungi or viruses) can enter the respiratory tract with every breath. This is precisely why the entire respiratory tract is lined with a highly specialized mucous membrane (respiratory epithelium), which is designed to protect our respiratory organs from harmful substances.
The respiratory epithelium is a layer of specialized epithelial cells, the ciliated epithelium, and serves to cleanse the airways. The ciliated epithelium is equipped with cilia, which are permanently in motion and are responsible for the removal of dirt and mucus. The mucus is formed by the so-called goblet cells. The goblet cells are mucus-producing glands that lie within an epithelial layer. Without this protective layer, pathogens can invade and lead to inflammation. Permanent inflammation (silent inflammation) can cause chronic respiratory diseases (such as bronchitis, asthma, or COPD) to manifest. Goblet cells are also found in the gastrointestinal tract. Dysfunction can lead to inflammatory bowel disease (IBD). Ulcerative colitis, for example, is a chronic inflammation of the mucosa of the colon in which ulcers can form in the intestinal lining. Various factors such as genetics, environment, disturbed intestinal flora (due to e.g. medication, malnutrition) can influence the development of IBD. The term "intestinal-lung axis" describes the interrelationship of all mucosa-bearing organs.
Human mucous membranes are the first barrier to the outside world. Protect yourself!