Abstract: A tube connection structure is disclosed, which includes a first connector and a second connector that are fitted together. The first connector includes an outer cylinder; a communicating section which is formed with a liquid passage in which a liquid can circulate in a fitted state, and an annular valve body which is provided around the communicating section and seals an outer cylinder opening portion in a non-fitted state. The second connector includes an inner cylinder which pushes the annular valve body in the fitted state, an inner valve body which seals an inner cylinder opening portion in the non-fitted state and is pushed by the communicating section advancing into the inner cylinder through the inner cylinder opening portion in the fitted state, and a first seal member which is provided at least on an inner peripheral surface of the inner cylinder opening portion.

Abstract: Disclosed herein is a tube mounted in a hole that makes a body surface and inside of lung parenchyma communicate with each other, the tube including: a main body portion that has a hole part having one end opened to the inside of the lung parenchyma and the other end opened to outside of the body surface; and a flow rate adjuster that is provided for the main body portion and adjusts a flow rate of air flowing in the hole part.