An insertion apparatus, including an object for insertion into a patient an insertion structure including an annular mounting structure having a mounting structure interior, the mounting structure containing a resilient membrane barrier extending across the mounting structure interior with a resiliently closing membrane opening for passing the object so that the object can be inserted forwardly through the membrane opening and into a patient and subsequently withdrawn from the patient and rearwardly from the membrane opening, the membrane opening resiliently closes as the object exits the membrane opening and thereby preventing patient bodily fluid from flowing rearwardly out of the insertion structure.
