Mucoasa

Mucoasa, or mucous membrane, is the moist lining that covers cavities and passages that connect with the exterior of the body. It consists of an epithelial layer, a supporting lamina propria of loose connective tissue, and, in some regions, a thin muscular layer called the muscularis mucosae. The type of epithelium varies by organ: in the respiratory tract it is often pseudostratified ciliated columnar with goblet cells; in the gastrointestinal tract it is mainly simple or stratified columnar; in the urinary tract it is transitional; and in ocular and reproductive surfaces it can be stratified squamous or other specialized forms.

Mucoasa are equipped with mucus-producing cells and glands that secrete mucus. This mucus, together with surface lubrication and antimicrobial components, helps trap particles, protect underlying tissues, and support local immunity. The lamina propria contains immune cells, blood vessels, and sometimes lymphoid tissue, contributing to defense and nutrient exchange. In some regions, the muscularis mucosae aids local movement of the mucosa.

Functions of the mucosa include acting as a barrier against pathogens, facilitating the passage and processing of substances (such as food in the gastrointestinal tract), enabling secretion and absorption, and supporting mucociliary clearance in the airways. It also contributes to humidification and conditioning of inhaled air.

Mucosa lines many parts of the body, including the respiratory, gastrointestinal, and urogenital tracts, as well as the ocular surface. Disorders affecting mucosa—such as inflammation, infections, ulcers, or neoplasms—can disrupt barrier function and fluid balance and may require clinical attention.