The main difference between mucous membrane and serous membrane is that mucous membranes secrete mucus, whereas serous membranes secrete serous fluids.
Body membranes are thin sheets of tissue that cover the body and organs within the cavities in hollow organs and line the cavities inside the body. There are two main types of membranes; they are the epithelial membrane and the connective tissue membrane. Of these two types, the epithelial membranes are thin layers of tissue that consist of an epithelial layer and a layer of connective tissue. The two main types of epithelial membranes are mucous membranes and serous membranes.
Key Areas Covered
1. What is Mucous Membrane
– Definition, Structure, Function
2. What is Serous Membrane
– Definition, Structure, Function
3. Difference Between Mucous Membrane and Serous Membrane
– Comparison of Key Differences
Key Terms
Mucous Membrane, Serous Membrane
What is Mucous Membrane
The mucous membrane is a thin layer of tissue that lines various body cavities and canals leading to the outside of the body. Mucous membranes contain mucus, which is later secreted to the outside. And, this mucus is a thick liquid that protects the inside of the body from dirt and pathogens. It specifically protects the internal environment of the body from infections of bacteria and viruses. Mucous membranes are made of a layer of cells. It is also of ectodermal origin. Additionally, mucosa or mucosal membrane has three layers: epithelium, lamina propria, and muscularis mucosa.
Some examples of tracts and structures that the mucous membrane lines are the urinary bladder, urethra, ureters, stomach, intestines, lungs, trachea, mouth, eyelids, esophagus, and nose. Specific mucous membranes have specific functions. For example, nasal and olfactory mucosae help odors to break down in the nose so that their particles can be detected and substances can be smelled. The gastric mucosa and intestinal mucosa help in the digestion and absorption of food. Mucous membranes can also be found in reproductive organs. It lines and protects the internal environment of the reproductive organs. In addition, vaginal mucus is a secretion by the vagina which keeps the vagina moist and helps in the self-cleaning of the vagina. It also plays a vital role in immunity. In fact, mucous membranes are the body’s largest protective layer.
Though mucosa is designed to act as a barrier against abrasion and infection, mucous membranes might sometimes get affected by pathogens. Fungi, viruses, and bacteria can cause mucosal disease in the mouth and genitals and sometimes the gastrointestinal tract. Some of these mucosal infectious diseases include mouth sores, mononucleosis, genital and oral lichen planus, oral and genital herpes, oral thrush, and genital yeast infections.
What is Serous Membrane
The serous membrane is a thin membrane that lines the internal body cavities and organs such as the heart, lungs, and abdominal cavity. The serous membrane is made of two layers of mesothelium joined by a layer of loose connective tissue and sitting on a basal lamina. Organs are surrounded by the internal visceral layer, while the parietal layer forms the walls of the body cavities. Moreover, the serous membrane forms an airtight sealing throughout the body.
Moreover, there are several types of serous membranes in the body. The pleural membrane that covers the lungs, the pericardium that surrounds the heart and some of the blood vessels, the serous membrane that surrounds the testes, as well as the peritoneal membranes that surround the abdominal cavity and related organs, are a few examples.
The size and complexity of serous membranes vary widely. For example, the peritoneum is the largest membrane with complex structures of convolutions, whereas the pleural membrane in the lungs is small and less complicated.
Furthermore, serous membranes have many functions associated with the protection of internal organs. Serous membranes allow frictionless motion between the membranes and organs without causing damage to the organs. Other functions of serous membranes include the production of cytokines and molecules involved in membrane repair and controlling immune responses like coagulation and inflammatory response.
Difference Between Mucous Membrane and Serous Membrane
Definition
A mucous membrane is a membrane that lines various cavities in the body and canals in the body that leads to the outside, while a serous membrane is a thin membrane that lines the internal body cavities and organs such as the heart, lungs, and abdominal cavity.
Secretion
Mucous membranes secrete mucous, whereas serous membranes secrete serous fluids.
Structure
Mucous membranes are typically thicker than serous membranes and have more goblet cells that produce mucus to help lubricate and protect the underlying tissues. Serous membranes, on the other hand, are much thinner and have a layer of simple squamous epithelium and a thin layer of connective tissue.
Function
Mucous membranes help protect and lubricate the body’s internal surfaces and help in the absorption and secretion of various substances, while serous membranes help to reduce friction between organs and reduce the spread of inflammation within the body cavities.
Conclusion
Body membranes are thin sheets of tissues covering the organs and cavities within the body. Mucous membranes and serous membranes are two types of epithelial membranes. The main difference between mucous membrane and serous membrane is that mucous membranes secrete mucus, whereas serous membranes secrete serous fluids.
Reference:
1. “Mucous Membrane.” Britannica Encyclopedia.
2. “22.5D: Serosa” LibreTexts. Medicine.
Image Courtesy:
1. “Layers of the GI Tract English” By Goran tek-en (CC BY-SA 4.0) via Commons Wikimedia
2. “Serous Membrane” By Connexions – (CC BY 3.0) via Commons Wikimedia
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