From the Alaska Airlines website...Just in case you need to know!

[fawnapril]

The following items may count as your "one" carry-on bag and may exceed the carry-on dimensions as long as they can be safely accommodated in a proper stowage compartment in the cabin of the aircraft.

* Art/Advertising portfolios
* Paintings
* Delicate scientific equipment
* Fishing poles
* Human organs (emphasis added)