Interoception is your brains representation of all sensations in your organs, tissues, hormones, blood, and immune system.
Intrinsic networks are pools of neurons that work together firing different groups each time but fulfilling a specific role (degeneracy). Intrinsic brain activity is the origin of dreams, daydreams, imagination, mind wandering, and reveries (collectively referred to as simulation).
Intrinsic activity is ultimately producing all of your sensations, including interoception. Intrinsic brain activity is millions and millions of non-stop interoceptive predictions, which produces our Affect.
The Intrinsic brain activity responsible for predicting our interoception is critical to managing the body's energy budget. We prepare for what we expect (e.g. increased pulse and blood pressure) rather than in response to what we do or experience.
The primary purpose of our interoceptive predictions is managing the body-budget, we predict not only what we expect to happen but what state our body should be in to respond.