Membrane

A thin, soft, pliable sheet or layer, especially of plant or animal origin.

A thin layer of tissue that lines a cavity, envelops a vessel or part, or separates a space or organ.

Thin, film-like, flexible, often translucent.

A very thin layer of tissue that covers a surface.

A thin layer of tissue (skin) that covers a surface or divides a space or organ.

Thin covering layer of tissue.

A thin layer of tissue that covers a body surface, lines a cavity, divides a space or organ, lubricates joining parts, or anchors a body structure. There are two principal types of membranes. Mucous membranes are mucus-secreting tissue such as those that line the nose and mouth; they lubricate the cavity and protect against infection. Connective membranes cover bone or hold body parts in position. Examples are the synovial membrane which lines the cavities of t he joints, and the eardrum, which separates the middle ear from the inner ear.

The physical boundaries of cells and cell compartments. Membranes exist as a lipid bilayer because phospholipids have amphipathic characteristics. They have both polar (the phosphorylated substituent at carbon 3) and nonpolar (the fatty acids) regions. The polar region is hydrophilic and is positioned such that it is in contact with the aqueous media around and within the cells. The nonpolar or fatty acid region is oriented toward the center of the bilayer so that it is protected from contact with the contents of the cell and the fluids that surround it.

Thin layer of tissue that covers an organ or lines a cavity or part (e.g., the pleura is a membrane enclosing the lung). It consists of two lipid layers in which globular proteins float. Membranes may be mucous, serous, or synovial.

A thin layer of tissue that covers a body surface, lines a cavity, divides a space or organ, lubricates joining parts, or anchors a body structure. There are two principal types of membranes. Mucous membranes are mucus-secreting tissue such as those that line the nose and mouth; they lubricate the cavity and protect against infection. Connective membranes cover bone or hold body parts in position (for example, the synovial membrane lines the cavities of the joints).

A thin layer of tissue surrounding the whole or part of an organ or tissue lining a cavity, or separating adjacent structures or cavities.

A thin, pliable layer of tissue that lines a tube or cavity, covers an organ or structure, or separates one part from another.

A thin sheet or layer of tissue that lines a cavity or separates two parts of the body. A membrane can act as a filter, allowing some particles to pass from one part of the body to another while keeping others where they are.