The part shows up because one of your authors/editors added a caption to the image when it was inserted into the post. You will have this problem not only with captions but with any other shortcodes that your authors/editors use. And you should be aware that WordPress includes several in its Core but various plugins and even themes provide a lot of them. You will need to process the shortcode:
echo apply_filters('the_content',$queried_post->post_content);
Or strip the shortcodes:
echo strip_shortcodes( $queried_post->post_content );
Which you do depends on the results that you want.
You should also be aware that echoing raw post content– ie. $queried_post->post_content— will probably not give you the formatting that you expect, because raw post content is not typically complete markup. Running the the_content filter, as above, sorts out most of that.