<p>Can someone provide an explanation of variable scope in JS as it applies to objects, functions and closures? </p>

Variables not declared with var are global in scope. 
Functions introduce a scope, but note that if blocks and other blocks do not introduce a scope.
I could also see much information about this by Googling Javascript scope. That's really what I would recommend.
http://www.digital-web.com/articles/scope_in_javascript/