What is an adjective that describes 'one way' and 'two way' flow?

Question

A few example are in order:

One way flow

1. An injection.

2. A river flowing into an ocean.

3. A mothers love.

Two way flow

1. Phone calls.

2. The flow of water between two oceans.

3. Herpies.

So, as you can see, all these things share the same property informally called 'flow', though it can only be one of two things in any point in time. As said property seems to be quite universal, I was wondering if there's an official term for what I dub 'one way flow', and 'two way flow'.

Answer 1

Websters gives the following definitions of unidirectional

1: involving, functioning, moving, or responsive in a single direction

2: not subject to change or reversal of direction

and bidirectional

involving, moving, or taking place in two usually opposite directions

I think those meet your needs. Specific to phone calls would be duplex for bidirectional. Half duplex communication is bidirectional but only one direction at a time.