Q: Why won't my Macbook Pro start?

I recently installed the latest versions of Pages, Numbers and Keynote. I restarted my computer when the update was complete. Now, when I try to start the computer, it gets to the grey apple screen and then shuts down.

I have tried resetting the PRAM and that didn't change anything.

I tried doing a safe start by pushing shift+command+v after pressing the power button. After a few moments the screen paused and the last thing on the screen was "Checking catalog file". It shut down shortly after displaying the following message:

Invalid record count

(4.10756)

**The volume Macintosh HD could not be verified completely.

What else should I try? Any help would be greatly appreciated.

Thanks.