When Visual Studio runs a build, it runs MSBuild to do the majority of the work. If you pass the .sln file to MSBuild, with appropriate Configuration and Platform properties
Visual Studio does not execute MSBuild.exe, but hosts the build engine itself (by means of the Microsoft.Build.* assemblies) - at least that is the case for the default C# project system. Other languages, addins, packages, etc. might do it differently.
Actually, there was a post series on the Microsoft blogs about this, I'm trying to find them and update this answer.
UPDATE: Found it again. Look for the "MSBuild in Visual Studio" posts here.
Concerning your original question, this page might help you further. Also you could go to "Tools", "Options", "Projects and Solutions", "Build and Run" and increase the MSBuild output verbosity. With "Diagnostic" you should basically see every property that is set upon starting the build.