Semi-permeable barrier between the outside world and your inside world. Allows passage of small things (e.g. viri) and moisture, but not big things (e.g. your fingers). Be kind to your mucous membranes, they stop you from melting.
A mucus-secreting membrane lining body cavities and canals connecting with the external air as the alimentary canal and respiratory tract.
Log in or register to write something here or to contact authors.