How far back does the tongue go?

The tongue doesn't really "go" anywhere in the sense of moving forward or backward. It's a muscular organ that sits in the mouth and is capable of a wide range of movements, including:

* Protrusion: Extending the tongue forward.

* Retraction: Pulling the tongue back into the mouth.

* Elevation: Lifting the tongue towards the roof of the mouth.

* Depression: Lowering the tongue.

* Lateral movements: Moving the tongue side to side.

The base of the tongue, which is attached to the floor of the mouth, is the furthest back part of the tongue. It extends from the back of the mouth to the epiglottis, which is a flap of cartilage that covers the opening of the windpipe during swallowing.

So, to answer your question directly, the tongue's base extends to the epiglottis, which is located in the pharynx (throat).