Question on one quiz answer unrelated to lesson topic

Question

In the quiz answer 'Cuando bebe leche, siente como si fuera a vomitar', why is 'siente' not 'se siente' used?

Answer

Hola Michael,
this is a very interesting question... 
The verb sentir can be used as a verb expression an "emotion" or a verb expression a "perception". For an emotion we use it as a pronominal verb with the reflexive pronoun "me siento fatal, se siente como una idiota, me siento como si fuera a vomitar". This is expressing "how" one feels. 
However, using this sentence without the reflexive pronoun will express how one perceives something, it is as if you were saying "I am perceiving/realising that I might vomit". 
In our sentence, we used it as a perceptive verb.
I can't see where you found this sentence in the system as it is not related to this lesson, but if you tell me I could have a closer look. 
I hope this clarified it.
Gracias y un saludo
Inma

Answer

I just quizzed the referenced lesson: "Using the imperfect subjunctive after the conjunction como si (subordinate manner clauses)", and it definitely is one of its 12 quiz sentences.

Your answer is a great addition to information in your A2 Lesson 'Sentir vs Sentirse (to feel)'.

Why I asked the question is because the sentence didn't seem to fit the pattern for using 'Sentir' from the A2 lesson, (ie) 'what' one feels, followed by a noun or que, neither for 'Sentirse', 'how' one feels, followed by an adjective, adverb, or como. I thought for a quick second that since 'Sentir' is followed by 'como si', 'Sentirse' should be used. But your concept of 'perception' vs 'emotion' explains the difference.