Código:
select name as [Foreing Key] from dbo.sysobjects where OBJECTPROPERTY(id, N'IsForeignKey') = 1 and parent_obj = object_id(N'<MiTabla>')
select name as [Primary Key] from dbo.sysobjects where OBJECTPROPERTY(id, N'IsPrimaryKey') = 1 and parent_obj = object_id(N'<MiTabla>')
solo sustituye <Mitabla> por la tabla que deseas consultar