membraanisiin

Membraanisiin is a Finnish adjective meaning membranous. It is used to describe structures or surfaces that are composed of membranes or that resemble membranes in their form or function. The term is derived from the word for membrane (membraani or membrana) and is used across scientific disciplines to indicate a relation to membranes.

In biology, membranous structures are common and essential. A membrane is a thin, flexible layer that encloses a cell, organelle, or compartment and regulates what passes in and out. Membranes are typically formed from lipid bilayers with embedded proteins, and they support processes such as selective transport, signaling, and compartmentalization. Membranous organelles include the nucleus (nuclear envelope), endoplasmic reticulum, Golgi apparatus, mitochondria, and chloroplasts in plants and algae. The term membranous may be used to describe tissues or surfaces that consist of or are covered by membranes, or to indicate that a feature has a membrane-like character.

Outside of anatomy, membranous can describe films or sheets of material that behave like membranes, such as thin protective films, vesicles, or barrier layers in materials science and food technology. In pathology and anatomy, the concept of membranes is central to understanding processes that involve separation, protection, or selective permeability.

See also: membrane, lipid bilayer, membranous organelles, vesicles, endoplasmic reticulum, nuclear envelope.