Raise a notification when a field is updated

Summary

Raise a notification when a field is updated

Content

We have 2 cases when we would like to raise notifications when a field is updated 

1. When a user updates a field from the UI. Then the integration should be sent a message from us to update the same field to a different system

2. When we are receiving a inbound call to update an activity, we would check the values and case of some value we would like to update a different field of the activity.

Is that possible? We havent found an activity updated trigger on message scenarios.