This is the url I used to get the info I needed. The key, I think, is the chaining of '&prop=extracts|pageimages|info' in the request.

$url='https://en.wikipedia.org/w/api.php?action=query&format=json&prop=extracts|pageimages|info&inprop=url&exintro=1&explaintext=1&exsentences=5&piprop=original&pageids=' . $item->id;
$x=json_decode(file_get_contents($url), true);  
dump($x);