All pull outs run their water through the flexible interior water line. It's not a "garden hose" though. Is that what you are asking here? Do you have a picture that better illustrates what you are asking?

Right ... if by "body" you mean the stylish part of the faucet.

It's hooked up just like the separate sprayers, but running through the faucet's delivery tube for the last inch or so at the sprayer end.

If by "body" you mean the metal part that holds the valves and input connectors, the water does contact that.

The flex hose runs entirely through the hollow faucet body (gooseneck) and loops down below the sink and then back up to the mixing valve outlet on the underside of the valve body; said mixing valve is fed by the hot & cold supply lines from the shutoffs.
Casey

This diagram should help you understand how these types of faucets are put together.