1. Muscle or nerve that causes an opening or enlargement of a structure in the body. 2. Instrument for opening a body orifice. 3. Drug that causes dilation or opening. See vasodilator.
1. Muscle or nerve that causes an opening or enlargement of a structure in the body. 2. Instrument for opening a body orifice. 3. Drug that causes dilation or opening. See vasodilator.