This allows choroidal fluid to leak into the subretinal space.

A very fine material, called a membrane, allows blood and fluid to flow through it.

Ear tubes allow fluid to drain out of the middle ear.

This allows excess fluid to drain out of the whipped cream so it will hold its shape better.

Ports are passages that allow fluid to pass through the valve.

Normally, the valve is open and allows fluid to pass through to the front brakes.

These were most likely respiratory in nature, allowing fluid to flow in or out of the body.

The first chamber allows fluid that is drained from the chest to be collected.

This allows the air or fluid to escape from the pleural space, and prevents anything returning to the chest.