If your clinic is satisfied with the results, they'll upload it. Otherwise, they'll give you a call and request you to come back again.
Once the clinic uploads the results to the e-medical system, the medical panel appointed by IRCC take a look at your file. If they are satisfied, they advise the VO and your medicals are set to passed. Otherwise, they (VO) might send in a request for additional tests (This is called "furtherance"). You have to take these tests and your clinic submits the results to IRCC.
They (IRCC medical panel) take a look at the results of these tests. If they are satisfied, they advise the VO and the medicals is set to "Passed".
However, if they deem that you are either a danger to public health/safety OR you are a burden to the publicly funded Canadian healthcare system, the process gets kind of complex. Check the below link to understand how the concept of Medical Inadmissibility works.
http://www.cic.gc.ca/english/resources/tools/medic/admiss/health.asp
http://www.cic.gc.ca/english/department/partner/pp/pdf/handbook-extract.pdf