Very good! It is almost perfect Greek!
Some notices: Λέγουμε is too formal, most likely use λέμε. About the verb λέω, it concerns the oral speech mostly, even we can use it in written texts. In this above case, it is better to use the the verb βάζω=to put instead of λέω, it is not wrong, but just more right.
About φυσιολογικό=natural, here. I am not sure what you mean by that, why it is natural, it is usual so, as it is in English, it is not like in Romance languages. This grammatical form is called epithet or attribute in English. But there is much flexibility about, it can be reversed to emphasize the adjective. Example: Είδα μια τεράστια χελώνα - Είδα μια χελώνα τεράστια (undefined which) And: Έφτασε και η ωραία Ελένη - Έφτασε και η Ελένη η ωραία: Ιn this case because it is defined who is the ωραία, that is η Ελένη, we repeat the article so, η ωραία.
To remember that the articles were initially definitions to the nouns, so they came. The difference with Latin is that Latin had no articles, so the Romance languages made articles from the Latin demonstrative pronouns (ille, illa, illud).
Yes. There is the English word physiological that comes from Greek. A second meaning is normal and a third one is natural. Of course Greek word means nothing to English. But this word, φυσιολογικός comes from φύση so as the closest to this is natural (from nature). Normal could be also translated as κανονικός as it comes from the word κανόνας=rule and the English word from the word norm, which almost similar. Which is the best in the above phrase? I think that having in mind the above, it is closer to use κανονικός=normal, as it is not something that is natural (from nature, I mean) . I have this sense.