The mucous membrane of the nose is composed of two distinct types of epithelium. One type is columnar, and the other is ciliated. Both types contain goblet cells and pyramidal cells. These epithelial layers are infiltrated by lymph corpuscles and serous glands.
Functions
The mucous membrane of the nose has several important functions. It traps pathogens and helps the body fight infections. The mucus contains IgA antibodies which prevent bacteria from invading the mucosa. It also has lysozyme enzymes, which help break down bacteria. The mucous membrane contains a deep layer of muscle cells. The mucous membrane is not part of the digestive system, but is vital for the body’s health.
The mucous membrane also contains glands and nerves. It also regulates the body’s immune response to allergens and infectious particles. As a result, it acts as a barrier to prevent allergens from entering the body and spreading infection throughout the body. The mucous membrane is sticky and traps allergens when they enter the nasal cavity.
Structure
The mucous membrane of the nose is made up of two main types of cells: columnar epithelium and ciliated epithelium. The former is columnar, and contains goblet and pyramidal cells. Both types of cells are infiltrated with lymph corpuscles and serous glands.
The upper portion of the external nose is made up of bone, while the lower portion is cartilage. It separates the nasal cavity into two passages, one for infiltration of air and the other for exhalation. The nasal septum, which is made of bone and cartilage, extends from the nostrils to the back of the nose. The septum is surrounded by nasal conchae, which are folds in the mucous membrane. This membrane traps particles in the air and regulates the sense of smell. Nasal polyps may develop between the septum and turbinates and are often found in patients with asthma, allergies, and cystic fibrosis.
Immune response
The mucosal immune system acts as a first line of defense against invading pathogens. In addition to regulating and inducing antigen-specific immune responses, it also creates an appropriate cohabitation situation between the host and outside environment. Foreign antigens are typically encountered through normal physiologic functions, and the mucosa has evolved clusters of lymphoid tissues that help initiate antigen-specific immune responses.
The mucous membrane of the nose consists of different types of cells, called dendritic cells (DCs). DCs form tight junctions with other cells and release antigens. Moreover, dendritic cells (DCs) send dendrites out to the nasal epithelium, where they sample pathogens directly.
Vascularization
Vascularization of the mucous membrane is an important feature of the nasal cavity. It allows dramatic variations in blood flow. Consequently, it can be affected by vasodilation and congestion. During necropsy, nasal congestion is frequently observed and is presumably related to circulatory failure. In addition, intraabdominal pressure and heart failure can increase intrathoracic pressure in the nose.
Nasal veins connect to the dural venous sinus (the sagittal sinus), which is a potential pathway for infection. Nasal veins are rich in blood and are responsible for nosebleeds. This blood supply is centered in the kiesselbach region, which is one of the most common places to suffer a nosebleed. Vascularization of the mucous membrane is a common feature of the nasal cavity, and it can be caused by a variety of conditions, including allergies, trauma, or even chronic conditions.
IgE production
IgE production in the mucous tissue of the nose can be induced by exposure to allergens. This immune response can result in increased mast cells and basophils, which provide more targets for IgE-allergen interactions. The nasal fluid also has increased levels of histamine, a marker for mast cells. In addition, nasal inflammation leads to an increase in the permeability of the mucous membrane, which makes allergen penetration easier.
Once the allergen is in the body, it is bound to the immunoglobulin receptors on mast cells. These cells then release mediators of inflammation. This process leads to the production of allergen-specific IgE antibodies.
Pathogen trapping
The mucous membrane of the nose acts as a barrier against bacteria and viruses. The mucus layer is constantly replenished and contains host-defending molecules. During infection, pathogens disrupt this layer and alter the environment in which commensal and environmental microbes can survive. When pathogens infect the mucous membrane, they reach the apical membrane surface, decorated with large cell-surface mucins.
The mucus membrane of the nose contains a dense network of capillaries, which serves as a barrier against invaders. The mucus is also made up of cells of the immune system that produce mucus and vibrate cilia. This barrier helps the respiratory system to function correctly. In addition to the mucus, the nasal mucosa contains immune system cells and substances that can fight bacteria.