Are those correct?
Yes, more or less.
They both seem very convoluted, is there a simpler way to say that?
Here are a few options:
"There's no reason for anything to be shown after the credits are finished."
"There's no reason for anything to be shown after the credits."
"There's no reason for anything after the credits."
Typical orienting reactions include the following.
Can be written as a complete sentence.
2.The arteries to the brain grow wider allowing more blood to reach it, the heart slows down and arteries to the large muscles become narrower so as to reduce blood supply to them.
Can also be written as a standalone sentence. Which in this case I suggest it ...
The sentence you quote was not written by anybody who was trying to be clear. But apart from lack of clarity, it is grammatically OK.
I think that you are understandably being confused by the very complicated noun-phrase at the end of this sentence. In outline it says:'The outcome (also) reflects [something]'. Something = 'the effect [x] has had on the ...
A walk at the park is essentially acting as a noun phrase where the word walk is not the verb to walk but the noun walk which is a thing that people do.
Therefore, in this whole sentence, there is only one verb: Took. This verb takes the past tense of take to be took.
So, applying that knowledge to this sentence in particular:
He took a walk at the park....