Noun. 1. mucosa-mucus-secreting membrane lining all body cavities or passages that communicate with the exterior. mucous membrane. conjunctiva-a transparent lubricating mucous membrane that covers the eyeball and the under surface of the eyelid.oun. 1. mucosa-mucus-secreting membrane lining all body cavities or passages that communicate with the exterior. mucous membrane. conjunctiva-a transparent lubricating mucous membrane that covers the eyeball and the under surface of the eyelid.
Relations vs Functions. In mathematics, relations and functions include the relation between two objects in a certain order. Both are different. Take, for instance, a function. A function is linked with a single quantity. It is also associated with the argument of the function, input, and value of the function, or otherwise known as the input.
One important kind of relation is the function. A function is a relation that has exactly one output for every possible input in the domain. (The domain does not necessarily have to include all possible objects of a given type.