The present disclosure relates to multiple embodiments of catheters (100, 200, 300, 400, 600, 700, 800) which include valved openings (118, 120, 218, 220, 318, 320, 418, 420, 618, 620, 718, 720, 818, 820) which are normally closed to maintain a lock solution within a catheter during periods of non-use.