Source : Webster's Revised Unabridged Dictionary (1913)

Physiologist \Phys`i*ol"o*gist\, n. [Cf. F. physiologiste.]
   One who is versed in the science of physiology; a student of
   the properties and functions of animal and vegetable organs
   and tissues.

Source : WordNet®

physiologist
     n : a biologist specializing in physiology