membrane
Meaning of membrane: A membrane is a thin sheet of tissue that lines, covers, separates, or encloses a body structure or cavity.
Definition of membrane
A membrane is a thin layer of tissue that lines, covers, separates, or encloses a structure, cavity, or surface within the body. Membranes vary widely in composition and function, ranging from thin sheets of cells lining internal cavities to more complex structures made of several tissue layers.
Some membranes, such as the mucous membranes lining the mouth, airway, and digestive tract, produce fluid that keeps the surface moist and helps protect underlying tissue. Others, such as the membranes surrounding the brain and spinal cord or those enclosing individual cells, provide a protective or structural boundary, and at the cellular level, the cell membrane regulates what enters and leaves a cell.
Because membrane is a general term applied to many different structures, its meaning depends on the specific membrane being described in a given anatomical or clinical context.
Used in a sentence
Imaging showed thickening of the membrane surrounding the affected joint.
Good to know
Membrane is a general anatomical term applied to many distinct structures throughout the body, so it is typically paired with a more specific name to indicate which membrane and location are being described.
Word origin
Where “membrane” comes from
From Latin membrana, meaning "a thin skin" or "parchment."