Vertical scrolling in a master view that contains UICollectionView and UIImageView

Vertical scrolling in a master view that contains UICollectionView and
UIImageView

I currently have a view set up in Storyboard comprised of an UIImageView
on top and a UICollectionView. The UIImageView has a fixed height, while
the UICollectionView has a variable height depending on the number of
cells associated with it.

What I am trying to figure out is how to set up the scrolling so that the
entire master view could scroll vertically, meaning that the UIImageView
would not stay locked on the top, and that when I scroll past a certain
height in the UICollectionView it could then perform some action such as
downloading more items to placed into additional cells?
Thanks!