A needle arrangement for a medical application, the needle arrangement comprising: an elongated needle sheath having an undivided front end surface provided with an opening and a rear end, and a needle comprising: an elongated portion adapted to be coaxially arranged inside the needle sheath and extending through the opening, and a sealing member being arranged to a front end of the elongated portion, wherein the needle arrangement is adapted to be set in: a closed position, in which the sealing member and the needle sheath are forced towards each other, wherein the sealing member is arranged to abut the complete front end surface of the needle sheath , the front end surface extending transverse the longitudinal axis of the needle thereby restricting intrusion of foreign matter in an area between the needle sheath and the needle, and an open position, in which a gap , extending in the longitudinal axis of the needle , is formed between the sealing member and the front end surface of the needle sheath , the needle arrangement further comprising: a connection member arranged to the rear end of the needle sheath and adapted to connect to an actuator or to a syringe , characterized in that the connection member comprises a biasing means arranged to bias the needle arrangement to be set in the closed position. an elongated needle sheath having an undivided front end surface provided with an opening and a rear end, and a needle comprising: an elongated portion adapted to be coaxially arranged inside the needle sheath and extending through the opening, and a sealing member being arranged to a front end of the elongated portion, an elongated portion adapted to be coaxially arranged inside the needle sheath and extending through the opening, and a sealing member being arranged to a front end of the elongated portion, wherein the needle arrangement is adapted to be set in: a closed position, in which the sealing member and the needle sheath are forced towards each other, wherein the sealing member is arranged to abut the complete front end surface of the needle sheath , the front end surface extending transverse the longitudinal axis of the needle thereby restricting intrusion of foreign matter in an area between the needle sheath and the needle, and an open position, in which a gap , extending in the longitudinal axis of the needle , is formed between the sealing member and the front end surface of the needle sheath , the needle arrangement further comprising: a connection member arranged to the rear end of the needle sheath and adapted to connect to an actuator or to a syringe , characterized in that the connection member comprises a biasing means arranged to bias the needle arrangement to be set in the closed position. a closed position, in which the sealing member and the needle sheath are forced towards each other, wherein the sealing member is arranged to abut the complete front end surface of the needle sheath , the front end surface extending transverse the longitudinal axis of the needle thereby restricting intrusion of foreign matter in an area between the needle sheath and the needle, and an open position, in which a gap , extending in the longitudinal axis of the needle , is formed between the sealing member and the front end surface of the needle sheath , the needle arrangement further comprising: a connection member arranged to the rear end of the needle sheath and adapted to connect to an actuator or to a syringe , characterized in that the connection member comprises a biasing means arranged to bias the needle arrangement to be set in the closed position. <EOS>