Answer: It's not blocked
https://www.khanacademy.org/science/high-school-biology/hs-human-body-systems/hs-body-structure-and-homeostasis/a/tissues-organs-organ-systems
After the adenylyl cyclase reaction (which convert ATP into cyclic adenosine monophosphate-cAMP), cAMP level is directly increased. Next steps of PKA activation include:
• cAMP binding to regulatory subunits of PKA, as a result conformational change in the regulatory subunits of PKA is induced,
• catalytic subunits are detached and unleashed by regulatory subunits and as a result activated.
The mountain lion population will decrease.
I believe the answer is Integumentary, Hope this helps ")