Head of the gate

Psalm 24:7-10 - Lift up your heads, O you gates;
be lifted up, you ancient doors,
that the King of glory may come in.

Who is this King of glory?
The LORD strong and mighty,
the LORD mighty in battle.

Lift up your heads, O you gates;
lift them up, you ancient doors,
that the King of glory may come in.

Who is he, this King of glory?
The LORD Almighty—
he is the King of glory.

I wonder if there is/was a piece of a city gate that is routinely called the 'head' or if David is anthropomorphizing these doors. In the former case, perhaps that's a part of the gate -- like a latch -- that needs to be moved before the gate can be opened. In the latter case, I don't quite see the connection between lifting up the head (of a person) and being able to open a door.