physiological reaction

NOUN
22 LETTERS · STARTS WITH P

physiological reaction is a valid 22-letter word worth 34 points in Scrabble and 39 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
P3H4Y4S1I1O1L1O1G2I1C3A1L1R1E1A1C3T1I1O1N1
3 + 4 + 4 + 1 + 1 + 1 + 1 + 1 + 2 + 1 + 3 + 1 + 1 + 0 + 1 + 1 + 1 + 3 + 1 + 1 + 1 + 1 =34 PTS
DOUBLE WORD → 68TRIPLE WORD → 102
MEANING

What does physiological reaction mean?